- "I like how the word rolls off the tongue. Besides, I have little interest in the petty power struggles of the upper ranks. I lost my elder sister to that sort of thing, after all."
- —Shinoa to guards on why she has the meager rank of sergeant[src]
Shinoa Hīragi (柊 シノア Hīragi Shinoa?) is the main female protagonist of the Seraph of the End: Vampire Reign manga series and the younger sister to Mahiru Hīragi. She is from the prestigious and rich Hīragi Family and was appointed as Yūichirō Hyakuya's supervisor during his suspension. She was a sergeant of the Japanese Imperial Demon Army and the leader of the Shinoa Squad (シノア隊 Shinoa-tai?) in the Moon Demon Company. She was ultimately possessed by Shikama Dōji, shattering away her humanity.
She also appears in the light novel series Seraph of the End: Guren Ichinose: Catastrophe at Sixteen as Mahiru's messenger.
In the light novels, Shinoa is described as a short, adorable, and beautiful young girl with shoulder lengthened ashen hair same as Mahiru's, and a large, dark pink bow at the end of a twisted braid. Guren describes her as having clear, piercing amber-red eyes that seemed to stare out at the world and skin so pale that it was almost transparent to her blood. On her left arm, she has a black shackle.
She wears a black sailor-like uniform with 10 yellow buttons along the side of the dress. Placed before the last set of buttons, she wears a silver belt, and on her hands are white gloves. There are 2 green stripes around the wrists of the uniform, and on the neck side, she wears a dark pink bow.
Shinoa has grown up but is shorter that alot of other girls. She has petite and thin figure and she now has hair is pinned up at the back with a magenta bow and side braids. After being possessed by Shikama Dōji, her eyes become a pale yellow with thinner irises and pupils.
At the beginning of the series, she is shown wearing her school uniform, a sailor fuku which consists of a grey blouse with black cuffs that have teal trim in the middle. It has a black sailor-style collar with has teal trim and a single five teal petal design in the middle. The ribbon of the uniform is also teal and is tied in the front and laced through a loop attached to the blouse. The bottom is a black skirt. She wore it with dark blue knee high socks and white shoes.
After Yūichirō was accepted into the Moon Demon Company, she is often seen wearing her Japanese Imperial Demon Army uniform which consists of a long-sleeved black coat with a standing collar which has a magenta bow tie around it. The coat has two rows of gold buttons on the front, light green details including the shoulder epaulets, which has a fourragère passing under and around her right side. Along with that, she wears a pair of white gloves, an armband on her left arm, and a white web belt with a gold waist-plate. She also wears the standard black skirt, dark gray thigh-high socks and knee-high black boots.
Her casual appearance doesn't differentiate much from her JIDA uniform. The minor differences are that she doesn't have her gloves along with the bow tie on her collar and wears a white long-sleeved dress shirt with a camisole over it.
Shinoa has a sarcastic, apathetic attitude and does not put much emotion into her words. She loves teasing others and is quite dry-humored. Shinoa generally tends to smirk before teasing or performing her antics towards others, placing them in uncomfortable situations. She can be proud and arrogant but has a nice, joyful and cheery part of her. Rarely, Shinoa shows that she can have a scary and manipulating side. Shinoa has made a contract with Shikama doji. This makes her part-demon. Her personality while fighting consists of a cruel, but quiet state. This causes her to give off a growling sense. At times, she lacks self-control and will get mad easily, increasing her tone and growling. Shinoa keeps her developing emotions for Yuichiro in reserve, as she says she wants to keep her feelings "professional" and because of this, she shows to have a tsundere side.
Due to her circumstances surrounding her family, Shinoa grew up without knowing what a sibling is, and never truly cared about anyone until her current squad was formed. She greatly respects Yūichirō's resolve and feelings toward his family and wants to help him. She shows surprisingly little emotions when talking to Yūichirō about her sister's death, suggesting that Shinoa is emotionally detached to people she knows and keeps her friends away at an arm's length.
In Catastrophe at Sixteen, Shinoa is revealed to be a lonely girl, shut away in an apartment on her own. The only friend she has is her older sister Mahiru, but in the end, the demon possessing Mahiru consumed her humanity, and that shattered Shinoa's resolve to form bonds with others. When Shinya and Guren offered to take care of her after seeing the mess in her apartment, she pushed them away, claiming that they are only there to use and exploit her. Shinoa's lack of faith in others caused her to believe that she can only rely on herself, as there is no one else to trust. Because of this, she trusts people less overall and is more negative about things, and messy if she is alone.
Shinoa shows that she does not care about the conflict inside her family, claiming that family conflicts are what caused the death of her older sister. Unlike Kureto, she lacks ambition and only wants to serve the army well. She explained to some soldiers that she does not actively seek a rise in rank, and her lack of ambition (and Mahiru overshadowing her) is what caused her to be cast out from her family.
However, it was not until after she lost the mock battle between her squad and Guren's three-person squad, did Shinoa finally realize the fear of losing someone important to her, and even a tiny mistake or her pranks can cost her family their lives. Also, she and her squad can grow even stronger and the closer they grow, the more powerful they shall become.
Shinoa has a vulnerable complex about her short stature when Yūichirō and Shihō teased her for being too short to drive a car, she laughs smugly before proceeding to materialize her Cursed Gear to physically teach them a lesson.
As a leader of her squad, Shinoa takes a calm and strategic approach to situations.
After being possessed by Shikama Doji, her personality changes drastically. She becomes merciless, violent and ruthless, attacking anyone who might pose a threat to her (under Shikama Doji's influence) this is largely shown when she attacks Ferid and Crowley whom Ferid tried to kill her. This follows Ferid breathlessly telling others to run from her. With Shikama Doji and her demon power in control, she also attacked Guren, Shinya, Kureto and Mika for no reason at all, just for her own amusement. She has also developed the power to cut off one's head with her fingertips or hands.
Shinoa, like her half-sister, Mahiru Hīragi, was conceived through artificial insemination by using the seeds of Tenri Hīragi in various demon-possessed women. The demon Shinoa was born with was Shikama Dōji, but somewhere in her early childhood, Mahiru somehow separated the demon from Shinoa in order to save her younger half-sister which causes Shinoa to forget about Shikama Dōji.
As a child, Shinoa was overshadowed by her older half-sister for being a genius and fighter prodigy that her father was looking for; hence, Shinoa was never acknowledged by her father along with most of her family and even lived alone in her own apartment. The only person she had was Mahiru, who often visited and treated her nicely to the point that Shinoa was willing to be her older sister's messenger until Mahiru eventually abandons her. Shinoa is eventually reunited with Shikama Dōji which causes her to regain her memories of him and gain the demon as her Cursed Gear.
While Mahiru is considered a hero for developing the Cursed Gears that the JIDA now relies on today, Shinoa ended up getting shunned by the Hīragi Family largely thanks to Mahiru's betrayal in siding with the Brotherhood of a Thousand Nights, starting the war between them and the Imperial Demon Army, and becoming possessed by the demon curse that lead to her death.
At some point, Shinoa is appointed sergeant and has been working under Guren.
Events of 2012
As Guren heads towards Hyakuya Orphanage, he sees Shinoa standing in the middle of the street he is walking on. Guren is able to tell immediately that she is related to Mahiru just by her hair. She introduces herself as Mahiru's younger sister. He asks her why she's here and she tells him that Mahiru has a message for him. When he sarcastically wonders why Mahiru would have a message for someone like him, she tells him that she knows who he really is as Mahiru told her. She recalls all the information that only Mahiru should have known to prove her point.
Guren asks her what side she's on and she responds by saying whichever side is most interesting. She says that honestly, power and influence seem boring to her and she was lucky to be born with a powerful sister since that means that she doesn't have to deal with the same expectations over the leadership of the Hīragi family. She adds that it's between Kureto and Mahiru and that she is mostly a backup in case the both of them die.
She springs forward, holding a fuda, which seems to appear out of nowhere. Guren notes the aura of danger rippling through her body and he finds it hard to believe that a small child could have this much power. He doesn't react to her attack. Shinoa stops mid-way and wonders why he isn't trying to counter. He responds by saying that if she's that strong, there nothing he can really do. He asks what she's trying to prove. She slips the Fuda back into her pocket before responding. She says that she was trying to prove whose side she's on and she's not interested in the Hīragis' or the Thousand Nights, but she loves her sister as she's always kind to her.
Moving back to the subject at hand, Guren asks what the message was. She says that the message is to not go to Hyakuya Orphanage as Mahiru is planning to betray the Thousand Nights. He asks her what Mahiru is planning and what she's going to do. Shinoa says that whatever she's planning is too complicated for her to understand, so Guren says to just tell him what she can understand. She says that all she knows is that Mahiru is trying to acquire enough power to ensure that no one ever comes between the two of them again and that Mahiru said that he's doing the same thing and that while their paths are different, their destination is the same.
He asks if that's all she knows which she nods which Shinoa says yes. Guren then tells her to deliver a message from him to Mahiru. He says to tell her that he doesn't like being manipulated by anyone; She's a fool and if she really thinks she loves him that she should stop playing games with him.
Just then, they hear voices from behind her. It's a group of children who look to be the same age as her; among them is a blond boy. Guren recognizes him as the one from the Hyakuya Orphanage, Mikaela. He runs up to Shinoa to see if she is alright, and she milks the situation by telling Mika that Guren told her all sorts of dirty things and that he was probably trying to abduct her.
Before Guren leaves, he tells her to not forget about delivering his message. As Mika threatens to call the police, Guren hears Shinoa cackling in delight.
Later, Kureto has her picked up from her apartment without warning one morning, and she does not have time to grab her wallet or shoes. Kureto has makeup put on her to make her look like she was beaten and had her fingernails torn off. He has her bound to a chair and uses this appearance to interrogate Guren. When she see him, she cheerfully says she is innocent and should be freed.
Guren's face contorts into an expression of disgust. Kureto comments about it, and Guren says he hates torturing kids. Kureto agrees but says such things do not matter for a Hīragi. He points out that Shinoa is smiling and says she has been trained to never let loose a single word during torture.
Guren walks over to Shinoa, pats her head, and releases her restraints. She asks permission to stand up, but Kureto orders her to remain seated. Kureto reveals that this is actually all makeup and Shinoa was not actually tortured. He says she would not reveal anything anyway. Shinoa stands up, saying she is bored. He commands her to stay and leave the makeup on for when he questions Shinya later.
Kureto says this was all to gather information and says he will trust Guren. Kureto says he already knows Guren met Shinoa, so he will kill Shinoa first. Kureto grabs Shinoa by the neck, and Guren charges him. Kureto blocks his attack and threatens to break Shinoa's neck.
Mahiru sends Kureto a message telling him to do as he pleases, and tears briefly form in Shinoa’s eyes. She listens to Kureto order Guren to meet and persuade Mahiru with a message requesting and wanting her to return to the Hīragi to the point that Kureto will permit her and Guren to marry to keep her in the family. He also tells Guren to hold her and never let her go or else kill her before she destroys everyone around her. He then sends Mahiru's IP address to Guren, and he asks whether Kureto or Mahiru is stronger which Kureto tells him Mahiru is stronger.
Mahiru then calls Guren, and Guren puts the phone on speaker for Shinoa, and Kureto to also speak to her. Shinoa reports that everything happened as Mahiru predicted, and reports that Guren, Kureto, and Aoi are listening to their conversation. When she asks about their father, Kureto reports that he does not know she is missing. She calls him a liar and accuses Kureto of her crimes, saying he actually did everything instead of her out of jealousy. He says no one will believe her. After they talk for a bit, she mocks Kureto for prolonging their phone call to track her instead of hanging up immediately. She reveals the special ops he sent after her just now are already dead. A student rushes in and reveals that this entire conversation was just broadcast over the whole school.
Shinya meets Guren and Shinoa once Kureto releases them, and he and Shinoa laugh about Shinoa’s torture makeup. Guren asks Shinoa how she feels about her sister. She says Mahiru would be the one most against her death while no one else would care at all. When Guren and Shinya both say they would be sad if she died, she says they only care about her as a replacement for her sister, whom they love so deeply.
Shinoa states it is clear Mahiru officially abandoned her today and will probably never contact her again.
The bell for fifth-period rings and Shinoa holds out her hand to request money from Guren. She says wants to take a taxi home. He says he is not interested in caring for Mahiru's little sister, but she and Shinya laugh. Shinya gives her a 10,000 yen bill and asks her to ask Mahiru if she remembers who her fiancé is.
Another day, Guren visits Shinoa at her apartment which is large enough for a couple or a small family. He finds her sitting in the dark with a blank expression. He notices there is no refrigerator, and the only things present in the kitchen are canned foods and a microwave.
Guren invites her to his house for dinner and says he has good cooks, but Shinoa does not trust him so easily. She says Mahiru told her Guren betrayed the Order of the Imperial Demons, and his father is being held hostage until his execution. Kureto sends Guren a message to keep an eye on Shinoa in case Mahiru contacts her.
Shinoa calmly throws a knife at Guren with an exploding tag on it, but he easily catches the blade between his fingers and tears off the talisman with his thumb. Shinoa comments that he is strong. She says Mahiru told her they had sex and teases Guren about it.
Guren steps out of the apartment with Shinoa at 6:15 p.m. They take a taxi, and the driver complains about being his previous job letting him go and how his two passengers are so fortunate to be born into wealthy families. He complains about the cozy life he believes Guren and Shinoa lead, which makes Guren laugh and makes Shinoa say he is being too talkative. They go onto the Metropolitan Expressway.
They hear a screeching sound, and Shinoa jumps out of the car while Guren drags the driver out with him. A dump truck falls onto the taxi and then falls onto a mother and child. Guren summons Noya and cuts the truck in half to save them. The civilians begin screaming.
Guren orders Shinoa to return home and gives her 10,000 yen for a taxi. He tells her to get a meal before going back and will stay to observe the situation a while longer. They tell each other to be careful and then split up.
Guren takes Shikama Dōji to meet with Shinoa within Mahiru orders. The traitorous faction attacks them, but Guren kills them quickly and incidentally drenches Shinoa in their blood. Shinoa loses consciousness as soon as she touches Shikama Dōji, but Guren manages to escape with her.
Goshi calls Guren and reports that Guren's apartment was set on fire by the traitors. Their phone call is interrupted. Guren steals a motorcycle and escapes, but a van chases and crashes into him. Traitorous soldiers face him, but Shinya attacks with Byakkomaru while pulling up on another motorcycle. Goshi arrives in a stolen minivan with the rest of their squad and picks them up. He says policemen are still chasing them. They ask Guren what they should do about the end of the world.
Events of 2020
Second Shibuya High Arc
In the year 2020, Shinoa is now fifteen years old and is tasked with supervising Yūichirō Hyakuya at Second Shibuya High after the latter gets suspended for repeated insubordination. She is given knowledge of his background, which allows her to understand Yu's antisocial behavior. When Yu joyfully asks the teacher to suspend him, Shinoa introduces herself and tells him to cooperate or she will extend his punishment. She also mentions his punishment will end once he makes friends.
After class, she stays after class with Yu, where she encourages him to make friends and tells him she knows his background through Guren.
When he does not believe her, she hands Yu a hand-written message from Guren to back-up her claim. She watches Yu vent his frustration after reading the note before they encounter Yoichi Saotome being tormented by bullies. Shinoa encourages Yu to help him in order to gain a friend, but before he begins beating up the bullies, she warns Yu last-second that harming a civilian will extend his punishment, leading to him getting hit.
Shinoa is next seen walking with Yu and Yoichi, with the latter two carrying snacks. She observes Yu's poor interaction with Yoichi in regards to the latter's desire to get into the Moon Demon Company, and calls Yu a monkey brain teasing him further over Yu's frustrations that he unable to join the Moon Demon Company by suggesting it is because he is a virgin. She listens to Yoichi as he explains his reasons for wanting to join until an explosion goes off somewhere behind them. An alert then follows that a vampire has escaped and is heading to the school. Shinoa orders Yu and Yoichi to go to safety while she contacts the Moon Demon Company, but can only watch as Yu rushes off to fight the vampire. Shinoa appears accompanying Guren to meet back up with Yu after his fight with the vampire. She watches as Guren refuses to let Yu into the Moon Demon Company until Yoichi comes up and hugs Yu until the latter passes out. Seeing that Yoichi has become Yu's friend, Shinoa tells Guren that he must uphold his end of the bargain. Once Yu wakes up, she welcomes him and Yoichi to the Moon Demon Company.
The day after, she teases Yu about being popular and starting a relationship because he received a love letter from the girl he saved, but Yu shows no interest in the letter; which leads to Shinoa explaining how humans must build up their population in order to survive. When Yu asks why he is still attending this school, Shinoa says that he is training to gain the power to slay vampires, and manifests her Cursed Gear demon, Shikama Dōji. Yu demands that she hand her demon over, but she informs him that he cannot use a demon that has already been contracted to someone else. He still goes in for the attack to test the weapon's strength and though Shinoa is impressed with his fighting skills, as he can go blow-to-blow with her, she notes on how just using a normal gear with great skill would not beat a Cursed Gear and proceeded to overpower him with a single powerful attack from her demon, proving her point.
When the boys who bullied Yoichi in the previous chapter chase Yoichi to beg for him and Yu to help their friend, who went into the Forbidden Chamber, she tells them that anyone entering one of the army's class-1 restricted zones is severely punished and possibly executed. In reality, the student was probably possessed by a demon. Nonetheless, she, Yu, and Yoichi decide to go down to the Chamber to save him.
On their way down, she reveals to Yu and Yoichi that the entire school is a training ground for the army where demons are kept in the basement. Any students who tolerate the aura without going insane are recruited to the army, meaning that students there either go mad or else join the army. She takes Yu and Yoichi into the shrine underneath the school, where they find the student Yūji possessed by a demon in an ax. Yu grabs the weapon, battling the demon in his mind. He surprises her by breaking free of the thrall of the demon's illusion by willpower alone, and he convinces her to password onto her superiors.
Upon meeting back with Yu, she laughs at his face, asking if he got in a fight. In reality, she knows that Shihō Kimizuki waited for him to measure his strength and is only playing dumb. When they pair up during class, she intentionally makes Yoichi her partner so that Yu is forced to pair with Kimizuki. At the end of the day, she informs Guren that Yu and Kimizuki are both candidates for the Black Demon Series weaponry since they both have strong desires and heart-breaking kindness. The strong desires would increase the power of the weapon while the kindness would prevent a takeover by the demon. Guren decides to prepare to take the throne out from under the main family, which is actually her own family.
Following the spellcraft exams being given back to all the students, Shinoa notices that Yu earned a zero on on his exam, and she snatches it, flaunting it about the whole classroom. When Guren tests the students to see if they are qualified to try for the Black Demon Series weaponry, she endures the test better than Yu or Kimizuki, although she is not as unfazed by it as Yoichi is. Although she is qualified to try for that powerful of a weapon, she already possesses Shikama Dōji, which is a lower level of Cursed Gear. Guren asks her why she did not pass out when she was supposed to, and she made it look so easy. Guren jokingly tells her to die. She then accompanies Guren, Yu, Kimizuki, and Yoichi into a chamber holding the Black Demon series weapons, and watches as Yu, Kimizuki, and Yoichi try for their Black Demon cursed gear.
Continuing with Yu and Kimizuki succeeding in gaining their cursed gear, Yoichi ends up becoming possessed. When Guren orders Yu and Kimizuki to kill him, Shinoa asks Guren to rescind his orders because it is too much for new soldiers. At some point, when the possessed Yoichi has his bow ready to fire, Yu tosses his weapon, Asuramaru, aside and calls out for Yoichi to fight back. This prompts Shinoa to summon Shikama Dōji and rush in with Kimizuki to defend Yu, but they pause when Guren begins calling out to Yoichi. To Shinoa's surprise, Yoichi, like Yu, also breaks free of the demon on his own.
On the boys' first day to battle with vampires, Shinoa is shown dressed in the JIDA uniform and waiting for Yu, who is also dressed in the same garb. The two complement each other's uniforms before she fills him in that they are assigned to defend Shinjuku from the vampires, who will be attacking the city from Kansai.
The two soon arrive at the outer wall, and their introduction causes the older soldiers to question among themselves why "kids" are joining the Moon Demon Squad. Overhearing them, Shinoa tells Yu that they think he is the kid in which Yu claims it's actually her, but she corrects due to her short height. She tells him that she is still growing as her older half-sister, Mahiru, was an attractive girl with large breasts. When asked that she had a sister, Shinoa tells Yu that she died in which he apologizes, but Shinoa tells him that people who survived had lost someone close to them in this world. The two then hear someone yelling at Guren as they reach their meeting point with Yoichi and Kimizuki.
They learn that Mitsuba Sangū will be joining their squad as their fifth member, but Mitsuba disagrees with Shinoa being the squad leader let alone being placed within this squad. Shinoa and Mitsuba have known each other for a long time, and Shinoa often addresses her as "Mitsu." Mitsu and Shinoa quickly get into a fight, and Guren breaks it up. After formally introducing Mitsuba, Guren instructs the squad to work on becoming an effective five-man team, and Shinoa asks Yu if he got those instructions which Yu confirms, but makes no promises.
The five are given their first mission to Harajuku, where they are to crush the vampire enclave and free the humans, and then make their way to Shinjuku. As the five make their way to Harajuku, Mitsuba goes into a lecture about the Horsemen of the Apocalypse, and Shinoa finds it cute that "Mitsu" is lecturing the new recruits. Upon arrival at Harajuku Station, they see a girl being chased by a Horseman, and Yu wants to save her. Shinoa and Mitsuba go against the idea because she is clearly bait, and it's impossible for a young girl to survive on her own in this world. At no surprise to her, Yu charges in and gets ambushed by vampires while she and the rest of the squad slay the Horsemen. When Mitsuba hits and scolds Yu, Shinoa tells him that Mitsuba also has a painful past.
Shinoa and Mitsu are next seen taking a shower. Mitsu rants about Yu's insubordination, and Shinoa teases her about falling in love with Yu. Shinoa tells Mitsu that the demise of her previous squad was not her fault, and Mitsu tells her to stay in her own damn shower. Shinoa promptly invades Mitsuba's shower, and screaming ensues.At the Omotesando Station Entrance in Tokyo, Shinoa briefs the squad on their orders and strictly forbids independent action. They slaughter the vampires successfully, but the livestock is terrified that they no longer have vampires to protect them from the Horsemen. They say that there is no room for them in Shibuya or Shinjuku or anywhere else controlled by the Demon Army due to their population regulations, which is in direct disagreement with what Shinoa told Yu earlier before. Considering that the cities are largely experimental grounds, there may be more behind these regulations than what the livestock know. Shinoa informs the livestock that there is now enough room in Shibuya to accommodate the livestock from the Omotesando Station.
Shinoa's squad then travels to Shinjuku. Shinoa addresses the Hummer that Kimizuki hot wired as the "Shinoa Dream-Liner" and gets in the driver's seat. Unfortunately, she is too short to see above the wheel, and Kimizuki and Yu have a blast laughing at her and calling her a runt. She beats them up, and they decide to not make fun of her height anymore.
On the way to Shinjuku, they encounter Thirteenth Progenitor Crowley Eusford and crash their short-lived Hummer into them. He attacks the squad, coming at Shinoa from behind, but Kimizuki defends her while Yu cuts off his arm. Shinoa decides how they should face him until Crowley's female aides arrive. Changing her plan, she orders her squad to go all-out, warning them that some of them may die. Fortunately, one of them tells Crowley that Ferid Bathory needs him elsewhere, so they leave. Shinoa is relieved, and explains to a frustrated Yu the importance of teamwork before thanking him for saving the squad.
Shinoa squad makes it to the gates of Shinjuku, where they fight off against a vampire invasion at the city's west wall. Once the vampires are taken care of, an intercom announces for the Shinoa squad to immediately aid Guren at the 5th Street Intersection.
Shinoa tutors the new recruits on drugging up. One pill increases the synchronization with a demon to 150%, and the second increases it to 180% but may kill the user by sending him/her into shock. Three pills rupture all of the user's internal organs. Furthermore, the pills only last a total of fifteen minutes before dropping the synchronization down to 0%. In order to watch out for this consequence, they use timers that go off after 13 minutes, so the user knows to run to safety before becoming defenseless. The supplement takes 10 seconds to take effect. The commanding officer gives the order to take the supplements.
Although she gives them that knowledge, the truth is that she gives Yu a different type of supplement under Guren's orders, which would cause him to transform and lose his mind shortly afterward. The squad soon reaches their destination in time to see Guren stabbed by a vampire.
After Yu and Mika reuniting, Shinoa learns from Yu that one of the vampires is Mika, one of his family. Seeing Crowley appear and Guren ordering a retreat, Shinoa advises Yu to leave Mika be for now; however, while Mika takes Yu away, the vampires ambush the squad, with Shinoa getting pinned and having her blood sampled by Crowley. He lets her go to avoid an attack from a berserk Yu, whom the latter then attempts to kill Shinoa.
When Yu attempts to stab her, Mika saves her life at great risk to himself by entering in Yu's way, having him instead get impaled in the back. Guren orders Shinoa to hug him, saying she can still save him, and the hug ceases Yu's transformation. Later, she attempts to get information about what happened from Guren, but he refuses to tell her anything, saying Yu will be fine in a few days and teasing that she might be in love with him.
After a week, Shinoa is there when Yu wakes up, and she teases him for crying about Mika. She lies about what happened in Shinjuku by telling him that he suddenly collapsed on the battlefield. She tells him a vampire dragged Mika away. Yu promises her to not attempt any sudden rescues right now. Yu touches her neck to look at her bite, making her blush tremendously until Mitsu walks in on them. It was completely innocent of Yu's part, confusing Mitsu. She tells Yu their squad is currently on leave.
Seven days since the battle in Shinjuku, Shinoa catches Yu in the Spellcraft Research Library again. She reminds him that he needs to rest on the doctor's orders, and holds back from telling him that the experimentation by the Demon Army caused his coma. She then teases him for reading dirty books; however, upon seeing a chapter about turning vampires back into humans, she asks Yu if he is looking to turning Mika back into a human. She tells Yu that she has information on vampire transformation. Shinoa tells him that only vampire nobles are permitted to turn humans, and a vampire's strength is determined by the noble that changed them. When Yu asks if she knew how to reverse the transformation, Shinoa shakes her head "no" before commenting on Yu's newfound maturity. An intercom announces for Yu to come to Shinjuku Central Army Headquarters First Office, which Shinoa says it is for the highest-ranking officers, mainly the Hīragi family. When Yu points out that her surname is Hīragi, she doesn't elaborate on it.
Shinoa then meets with Mitsuba and learns that Mitsuba got promoted to Second Lieutenant, which Shinoa says she got it just for being a Sangū. When Mitsuba brings up Shinoa getting promoted because for being a Hīragi, Shinoa says she would never get promoted and would turn down an offer if she did receive one. She then tells Mitsuba how the actions and prodigal talent of her older sister, Mahiru, lead to the Hīragis having no need for Shinoa, and she considers this a good thing as she has no interest in the power struggle, especially against her older brother, Kureto.
When the topic transitions to Yu's meeting with the Hīragis, Shinoa asks Mitsuba how much information she bribed the higher-ups with to get that promotion. She tells Shinoa that she told them that Yu was on their side, and did not tell them about him going berserk. When questioned if she knew more about what happened, Shinoa doesn't bring up her meeting with Guren. When Mitsuba voices her concern for Yu, Shinoa teases her for falling in love with him to Mitsuba's chagrin. She moves up to them with Kimizuki and Yoichi beside him.
Sometime after, Shinoa meets with Yu on a rooftop. She notes that he is early, and teasingly asks if he was watching for any women changing. Yu tells her that he is in the western direction, which is where Mika is being held and wants Shinoa to accompany him in liberating Mika. Shinoa notes Yu's newfound appreciation for friends, which Yu confirms and holds her hand and she blushes.
Guren then arrives, and after some banter between him and Yu, Guren tells him that Shinoa and Mitsuba know how to use cursed gear. Shinoa demonstrates how a manifestation type demon works by calling Shikama Dōji to her and explains how these demon types come out to use its special power. When Yu comments on Shikama's quietness, Shinoa tells him that demons are unable to fundamentally speak outside the heart of their hosts.
When Guren demonstrates to Yu the power of the possession type, Shinoa hears Guren call out Mahiru's name when he has his weapon possess him. After Guern throws Yu from the rooftop, Shinoa asks Shikama to kill Guren and was able to get behind him and holds the blade of her scythe to his throat. She reveals that her weapon specializes in mid-range combat and consequently stands no chance against a melee fighter like Guren at that range.
Guren calmly says he would let Shinoa kill him which she asks him if that is his way to atone for killing Mahiru. She asks if her older sister is in his sword since she heard him call her name. Guren says that Mahiru is already gone since she turned into a demon and saved the world by completing Cursed Gear. Shinoa laughs, stating that Mahiru was never one to care about the world because she loved him. She longed to be with him since they could never be together and became obsessed with demons.
After discussing the events of eight years ago, Shinoa says that if Mahiru hadn't completed the development of Cursed Gear, humanity would have perished. Her sister, who was just a girl in love became something like a Messiah, but then she was killed when she became obsessed with her research and became a demon. Shinoa continues saying, the one who killed Mahiru was the person who used to be her lover, him, Guren.
She asks him if Mahiru is together with him inside his sword, stating that he is being possessed by her. Guren asks her if she and Mahiru ever got along. She explains that she was not close with her sister because Hīragi's are raised without knowing familial love. He tells her to shut up and drop it. Shinoa then tells him that watching a "certain someone" get so desperate to save someone he has no blood ties to made her wonder if she should put more value into "friendship" and "camaraderie."
From that, she asks if making use of Yu was one of Mahiru's orders and asks if her sister or the demon for lack of a better word that is inside his sword is ordering him. She asks what his goal is, though he doesn't say anything. As if warning him, she asks that if his goal is something that does not benefit Yu, that she'd appreciate if he stopped. Guren sighs and asks if she seriously is head over heels for him.
Much later in the day, Shinoa squad are in a destroyed part of the city for Yu and Kimizuki's advanced training with their cursed gears. Shinoa educates Yu and Kimizuki on possession and manifestation typed demons and then has Yu and Mitsuba spar as a demonstration to show what each demon type does. She about jumped in to attack Yu when the latter cuts down Tenjiryū clones with Asuramaru.
Shinoa then talks about manifestation type demons, the type of cursed gear that she, Mitsuba, and Yoichi wield, in that using these demons' special abilities leave the hosts vulnerable and how each demon works best at certain ranges. Shinoa demonstrates by having Yu's sword touch her scythe, and summons out Shikama. This causes a push back of energy that knocks her to the ground, and Shinoa uses the demonstration to emphasize the importance for possession type users to protect their manifestation type comrades, which Yu promises he and Kimizuki would do while extending a hand to help Shinoa up.
She then goes back to the topic of possession type demons, where she informs Yu that he demonstrated it when he cut down Mitsuba's decoys. Shinoa tells Yu that they will be going a step further from possession, and instructs him to call on Asuramaru and have the demon drink his blood. When Yu comments on how that sounds like what a vampire does, Shinoa tells him that vampires and demons are related and asks if he wants an explanation for it. Yu decides to go first with the training and falls unconscious. Shinoa tells the squad that it will take twenty hours before Yu's able to join with his demon, and them being far from the city is for the case of him going mad.
She then learns from Kimizuki that he and Yoichi were questioned by the Hīragi about Yu going berserk at Shinjuku, and asked if withholding this from them is right. Shinoa answers yes, and tells Kimizuki that he is actually gentle before she agrees to tell Yu everything that happened.
That night, she notices Kimizuki's kindness and tag-teams with Mitsu to ship Yu and Kimizuki as a couple, which Kimizuki instantly rejects.
Once Yu wakes up, Kimizuki's training begins. They are using special abilities, which should be impossible for possession-type demons. She says the three Black Demon Series users may be Guren's handpicked secret soldiers. The detailed reports on their past have been removed from the army's intelligence department.
The squad meets in Shinoa's room in the barracks for breakfast. Mitsu sets an omelet on fire, but Kimizuki saves them. Starting a serious conversation, Shinoa takes the opportunity to tease Kimizuki, saying that he is gay, which he vehemently denies. She tells Yu he was part of an experiment that made him lose control and attempt to kill her on the battlefield. The group discusses Guren, and they decide to follow him anyway. She makes her squad's official policy "Family takes care of family."
Following their meal, the squad makes their way to the Ebina rest stop. When they come across a few Horsemen and Yu leaps out to slay them, Shinoa and Mitsuba prank him by ditching him on the road and making him wait ten minutes before they drive back to pick him up. After Yu gets behind the wheel, she tries the same thing on Kimizuki, but he catches up to them with a sword each pointed at Shinoa's and Mitsuba's necks. The say the joke was Yoichi's idea, but thanks to her pranks, they arrive late and has Guren yelling at her until Yu takes the blame. At the sound of Yu's screaming, the rest of the squad charge in to see a crying and naked Yu, Shinoa quickly sees that it was an illusion and has Shikama Dōji destroy it. Guren reveals this punishment is for her. He says Shinoa does not get it since she has never had anyone important to her before and does not know what it is like to fear losing someone. Guren then challenges her to a battle: himself, Mito Jūjō, and Shinya against her entire squad. Shinoa and Mitsuba quickly explain their abilities and give out orders.
In the fight, Mito temporarily disables Shinoa's scythe, and Guren disarms her once she regains control. They analyze their sound defeat, and Mito informs her that she was utterly incompetent as a squad leader. Once the formation was broken, Shinoa should have ordered her squad to withdraw immediately to prevent further casualties.
Shinoa then has the squad meet Sergeant Makoto Narumi, and they head to Nagoya. Narumi commands both of their squads, and they attack Fifteenth Progenitor Lucal Wesker. Lucal grabs her scythe and swings her into Narumi's path, but Yu protects her. They defeat the fifteenth progenitor without further incident. Narumi's squad high-fives each other, and Shinoa really wants to do it too, making her squad wonder if they have to.
The Moon Demon Company regroups, and Sergeant Aiko Aihara arrives with only seven survivors from her squads. Narumi jokes that Shinoa's excellent work as team leader was what got them by unscathed, and she does not manage a comeback quickly enough to avoid glare from Aiko. Guren Squad, Shinoa Squad, and Narumi Squad leave to hunt Crowley Eusford, Chess Belle, and Horn Skuld while Aiko waits for other survivors to pass them the order to reconvene at Nagoya Airport.
Once they reach Nagoya City Hall, Guren informs them that hostages are being used as bait to lure them; however, when his plan involves abandoning the hostages, Yu argues that they should be saved no matter what. Shinoa gets between them and asks Guren what their priorities are. In order, he says that their top priority is to: maintain their numbers, letting no one die; free the hostages, and get them out alive. Narumi states that they are needed for another mission after this, and Guren further explains they need to keep the vampires occupied in Aichi Prefecture for as long as they can to buy enough time for the main forces in Shibuya to prepare.
Following the failed snipping on Crowley, Guren and his squad discuss what to do. After careful planning, Guren decides that his squad will take his squad to attack Crowley while Shinoa and Narumi Squads free the hostages. He gives them five minutes to rescue as many hostages as they can and act as a proper diversion for the main force in Shinjuku. As soon as the five minutes are up everyone has orders to retreat to the Nagoya Airport immediately.
Yoichi eventually reports on the situation with Guren's squad to the others and Yu insists on rescuing him. Shinoa agrees with him but says they only have five minutes. She gives them specific instructions regarding their plan. Shinoa Squad runs through Nagoya City Hall, and Shinoa tells them that the enemies are directly above them and uses Shikama Dōji to scout the enemy for her. Shinoa counts down using her fingers and everyone prepares their Cursed Gear. After engaging Crowley, Chess and Horn block Mitsuba's attack. Shinoa says they've failed and tells everyone to pull back and regroup. The timer goes up and Shinoa tells Yu that it's been five minutes are up and orders a retreat.
Outside, Yu breaks free of Kimizuki's grasp and complains about leaving Guren behind. Shinya tells Shinoa to shut him up, so Shinoa asks Yu if he remembers the promise they made before this started: after five minutes, they would withdraw no matter what. She says that Shinya has known Guren far longer than him yet he is putting his feelings aside to escape.
After Yu's flashback, he wipes away his tears and states he cannot follow orders. He says he is not cut out for teamwork. He tells the others to proceed without him, and he will stay behind. He takes out his pills and realizing what he is about to do, Shinoa yells at him not to do it as taking two or more curse stimulant pills at once will kill him. Yu throws the pills up into the air and responds by saying that if he can't save his family that he'd rather die anyway. He catches the pills in his mouth and swallows them.
Shinoa grasps his shoulders worriedly and asks if he thought about what he's doing. She asks him how many pills he took and he says two. Shinoa yells at him to spit them up right now as he has taken three pills within a short period of time. Yu begins to cough blood and the curse power overwhelms him, forcing blood out of his eyes and making him scream.
When Yu awakes, Shinoa tells him again to spit up those pills. He says he is okay and has something to do. With immense speed and power, he leaps from the ground and breaks through the wall to reach Crowley.
After Kimizuki captures Yu, he joins with the rest of the squad, they run toward Shinya, who orders them to move. Vampire reinforcements are coming. They join with Narumi Squad and many injured soldiers. They flee, and Rika Inoue reports seeing a single vampire straight ahead. Shinya says they can handle one noble and orders them to keep pushing forward.
As Mika engages the Moon Demon Company, Shinoa calls out to Mika to identify him, but he tells her to shut up and return Yu to him.
After Shinya stabs Mika, Shinoa activates Shikama Dōji and knocks him away from Mika, surprising both of them. With her back to Mika, she explains that Yu would be mad at them if Mika were to die. She orders Mika to take Yu and run.
The other soldiers demand to know what she thinks she is doing and say they must kill that bloodsucker. Kimizuki, Mitsuba, and Yoichi join Shinoa, stepping between Mika and the other humans as well. Yoichi says that they've already decided on their motto: "Family takes care of family."
Shinoa tells Mika to hurry up and then meet up with them at Nagoya Airport. Mika asks her why he would meet up with them, but she says she decided to trust him and that is that. Her squad charges at the Moon Demon Company while Mika flees with Yu.
When Shinoa watches them leave, the other humans knock her down, calling her a traitor and telling her to die. Shinya tries to interfere and orders them to not kill her, but Makoto stops the sword of one of the men and asks him if he heard the major general's orders. When the soldier protests, Makoto punches him. He states that those who cannot listen to orders on the battlefield do not belong in the Moon Demon Company. Shinoa sighs with relief, but Makoto bonks her on the head and says she has a lot of explaining to do.
Shinoa is shown by herself at the Nagoya Airport, where she asked Mika to meet her and the squad. She appears out of breath, having run there.
The Shinoa squad, sans Yu, run in the Nagoya Airport for their rendezvous. Mitsuba says the attacks against them have stopped, but the vampires are most likely still pursuing them. Kimizuki asks Shinoa if she has more information on their assignment.
Before Shinoa can answer, Rika Inoue approaches and grabs her by her bow and yells at her for being alive. In tears, Rika blames Shinoa for the deaths of her comrades because she protected a vampire. She then punches Shinoa, and Shinoa stops Kimizuki from interfering. Shinoa apologizes, but Rika does not accept it and draws her sword. She knocks Shinoa down and gets on top of her, telling her to apologize with her life. Shinoa orders her squad members against attacking Rika. Rika does not stab Shinoa but yells at her to give her friends back.
Makoto Narumi touches Rika's shoulder and tells her to calm down. He says he will take it from here since he is the squad leader. Then, Shinya Hiragi arrives with Guren Squad, sans Guren, and Shinya says it is not up to Narumi who is disciplined.
Suddenly, a van pulls up and Aoi Sangū steps out. Although she notices Mitsuba, she quickly turns from her. Then, Kureto Hiragi steps out. Shinya Hiragi and the members of Guren's squad are immediately alarmed, surprising Makoto Narumi with their reaction. Yoichi and Kimizuki recognize Kureto as the one who tortured them. Shinoa and Mitsuba are concerned.
Kureto identifies himself and congratulates them on their successful mission. He says that thanks to their glorious sacrifices, humanity will now achieve complete victory over vampire-kind. He says he will take over now and orders them to put down their weapons and be at ease, but Shinoa orders them to hold onto their weapons, telling them that she feels that something terrible will happen. After Kureto orders Aoi to kill the "sacrifices", Shinoa orders her squad to quickly prepare to retreat.
As Aoi launches chains from the ground, a pair of chains strike down at Narumi from above, but Mitsuba and Kimizuki block the attack. Kimizuki yells at him to not give up yet. Yoichi fires arrows at Kureto, which Kureto easily deflects. Both Shinoa and Mitsuba order a retreat, with Shinoa commanding them to take their curse stimulant pills.
Kureto tells Shinoa that he will let her live so long as she obeys him, but she orders everyone to flee. Kureto orders her death, and three chains launch at her. Yu suddenly appears and deflects the attack, surprising Shinoa.
Yu and Mika step into the fray, shocking the Shinoa Squad and Narumi. Mika points out that humans are killing humans and tells Yu they should not have come here, but Yu disagrees. Yu asks Shinoa for orders, and she issues a retreat. The survivors all request to be backup for the rear guard, but Mika says he can block chains at that speed on his own.
An army of vampires arrives, cursing the insolent humans for their recent attack before they and the humans wage war. Shinya orders the Shinoa Squad to run while he and the Guren Squad back them up, so the younger squad flees while fighting through the crowds.
Seeing Guren go along with Kureto's plan, which includes chains wrapping around his arm as the curse consumes him, Shinoa supports Mika's warning to Yu to leave Guren, since he is not acting like himself.
The experiment continues, and the demon Abaddon is successfully manifested. Yu then awakens in his seraph form. He defeats the demon and later stabs himself through the chest with his cursed gear. Shinoa tries to ask Guren what is going on, but she sees Shinya point his gun at Guren and realizes that their escape is up to her now.
As the squad makes their escaped from Nagoya Airport, Shinoa tells her squad that they are now seceding from the Japanese Imperial Demon Army. Human soldiers chase them and order them to hand over Yu, who is now unconscious and on Yoichi's back, but Mika appears and kills them. Shinoa orders them to flee.
Three months later, the group is near the sea, with Shinoa being seen carrying some laundry.
After three months, Shinoa, Kimizuki, and Mitsuba listen to Yu and Mika's exchange from outside.
After Mika checks on Yu, Shinoa states it has been exactly three hours since Yu transformed and greets them.
She mentions it has been three days since Mika drank any blood, but Mika tells her he never asked her to be his keeper. Yu offers his blood, but Shinoa says Yu is too weak and has a bottle containing blood from everyone for Mika to drink instead. Shinoa examines the chains and says the wards for sealing the demon are beginning to crack, so she and Mitsuba will have to repair them again. Mika accuses her of pretending to be Yu's friend and points out that everything that has happened to Yu has been due to an experiment. Yu says that Shinoa did not get directly involved, but Mika says he cannot trust any of them. Mika asks what Guren did to Yu.
Shinoa tells them they are not themselves when they are hungry and suggests they get breakfast. She holds the bottle of blood out to Mika, but he knocks it out of her hand. Mika appears frustrated, and Yu scolds him. Mika says he is not Shinoa's pet, but Yu says that blood belongs to their friends.
A human rushes in and addresses Sergeant Shinoa, asking for her help. The Horsemen are attacking their village. With the exception of Makoto, their group fights four Horsemen. Afterward, the villagers thank them. Shinoa says this is the least they can do in exchange for their food and shelter.
Their group notices that Mika drank their blood and approach him. Yoichi asks if their blood was okay. Mika says it was gross. Shinoa rambles about the pure and sweet blood of a virgin and then asks if unchaste blood got in there before looking at Mitsuba with an aghast expression. Yu, Mika, and Shiho share identical blank expressions.
Shinoa brings up their future plans. Mitsuba summarizes what has been going on. She says that the Japanese Imperial Demon Army will probably hunt them down and kill them, which puts the villagers at risk. They mention they cannot travel overseas because of how acidic and poisonous the blood-red oceans are. Monsters even worse than Horsemen swim in their depths.
They suggest surrendering, and Mika rejects the idea of returning Yu to the army to prevent him from becoming a demon. Yu suggests meeting up with Guren, but Shinoa vetoes that idea and says they cannot trust him. Makoto tells Mika this is the circle of discussion they are stuck in and asks if he has anything to offer.
Mika asks if he owes them a favor because they gave him blood, but Shinoa says no. She says that blood was for helping a friend but says she would love to hear any suggestions if he has them.
Mika says the vampire queen, his sponsor, participated in the Seraph of the End experiments. They may be able to trust her. He says she was captured and he does not know what happened to her, but rescuing her might be their least complicated option. Makoto asks if vampires are less dangerous than the Demon Army, and Mika says yes. Vampires actually care little about humans and are only concerned by power-hungry humans. Makoto agrees and says that describes the Demon Army pretty well. Shiho also agrees with that plan and states he does not trust anyone aside from those standing right there. Mitsuba agrees to the plan, and Shinoa says that the Demon Army is the most dangerous organization in Japan.
Shinoa announces their next objective is to rescue Krul Tepes before Yu becomes a full demon.
While Yu and Mika discuss Ferid, Narumi asks them to stop talking over their heads and explain what they were talking about. Shinoa begins to explain that Yu and Mika were held in the vampire capital when they were little, but Yu notices a strange sound. Mika says it is a car engine. Yoichi runs to investigate.
Yoichi uses Gekkoin to spot the car which is being driven by Crowley, "the red-haired monster" they fought in Nagoya and is accompanied by a smaller, silver-haired vampire, whom Mika identifies as Ferid. When Shinoa asks why are they coming here, Mika says he does not know but advises their group to have nothing to do with Ferid and company.
With that in mind, Shinoa orders the squad to take their curse stimulant pills and run. As they are running, Shinoa comments on how Crowley and Ferid's ranks are leagues above everyone's abilities if they catch them, and tells Yu that they are all friends in this messed up world. Suddenly, Crowley lands in front of the group and attacks Mitsuba.
With Yoichi and Kimizuki attacking Crowley, Shinoa and Narumi join in to save Mitsuba.
When Mitsuba refuses to let go of Crowley, he says he will just cut off her arms, but Shinoa steps in and blocks his sword with her scythe.
The squad continues to fight Crowley until Yu tells him that he surrenders. Seconds later, Ferid arrives and provokes Yu and Mika by presenting them with Akane's head in a jar. This sends Yu's demon out of control, and Shinoa runs in to stop him. Mika gets to Yu first and him to struggle against the demon. Shinoa then asks Mitsuba to use the enchanted shackles to restrain Yu, but Narumi expresses concern that it won't work on a rampaging demon. The squad decides to call a truce with the two vampires, and Ferid reveals a drug that will help with Yu's demon.
After Ferid gives the squad Akane's head and administering the drug to Yu, everyone departs on a bus with Ferid and Crowley is driving. As they discuss the situation, Shinoa says they require Yu’s medicine and information, but Mika warns them that Ferid is completely manipulating every last one of them.
The group takes a bathroom break. Mitsuba reports that the exits at the rest stop are clear. Shinoa teases her, saying that she is using that as an excuse for taking a dump. Shinoa says that Ferid, Guren, Mahiru, and the Demon Army are all equally untrustworthy. They can only trust their friends inside the rest stop. The girls then enter the boy's bathroom where they discuss their situation and the Seraph of the End. Changing the subject, Shinoa asks how the boys use a urinal.
Going back to the topic at hand, they decide they must betray Ferid before he betrays them. Mika tells them they are not capable of killing him. Yu mentions that Asuramaru may be able to kill Ferid if Yu lets him take control for three seconds, but Kimizuki says demons are even worse than vampires. Shinoa mentions they cannot trust a single adult still alive.
They crouch together and whisper to come up with a signal of when to attack Ferid en masse.
Shinoa and the team are back on the bus, where at some point, Crowley slam on the breaks unexpectedly to throw Ferid through the windshield and have Yu hit his head, and Shinoa and Yoichi look at Yu with concern. The group then disembark, and Shinoa identifies the place as Osaka Bay.
The group gets surrounded by an army of foreign vampires, and they watch as one of them, Third Progenitor Lest Karr, pulls out Ferid's heart until being told by Second Progenitor Urd Geales to return it. The group then watch in horror as Ferid drinks from Kimizuki, which prompts everyone (except Mika) to take refuge on the bus. Shinoa sees Yoichi go to the back to rest before turning her attention to Mika. She asks Yu if Mika will be alright, which he says yes and apologizes for getting Shinoa mixed up in all of this. They then see Ferid and Krul being dragged back by Lest and Urd, and Shinoa alerts everyone that they are back. She watches as Ferd and Krul are subjected to sunlit torture, and goes with Yu's plan to rescue them.
Later, Shinoa Squad goes to Ferid's mansion in Osaka. Tenth Progenitor Fuola Honte appears from the mansion and attacks them. Shinoa begins giving instructions, and Fuola Honte cuts both of Mika’s arms off. Alarmed, Yu rushes forward while activating Asuramaru’s power to the breaking point and ignores Mika’s warning to stay back. Yu blocks the attack and Shinoa has Shikama Dōji pull them away from Fuola.
Crowley then steps out of the mansion, coming after Fuola. Fuola attacks Crowley, but the latter beheads him before slicing him in half. The group comments on Crowley’s strength, and Shinoa says she will not complain about their allies being too powerful. Crowley then spars against the squad and reveals his strength is at the level of a seventh progenitor. Since they have decided to rescue Krul and Ferid, Crowley tells them they must get stronger quickly since they had difficulty fighting a tenth and must face a fifth progenitor, Ky Luc, in order to rescue them.
Shinoa watches Yu and Crowley enter Ferid's mansion while the rest of the squad stays outside. Shinoa is surprised that Yu is not scared of Crowley and Mika replies that it's because he is an idiot. They describe vampires as apex predators who prey on humans and are nearly impossible to kill. The squad watches as Narumi test Mika's humanity, and they learn that Mika's emotions are fading, though his feelings for Yu have not changed. They then go into Ferid's mansion looking for food and Crowley directs them to the kitchen.
As the boys are raiding the kitchen, Shinoa and Mitsuba explore the upper level of the mansion. Shinoa peaks into one of the rooms to discover it to be a large, fancy bathroom. When asked by Mitsuba if its right that they are not helping the boys in the kitchen, Shinoa says that Kimizuki would get mad at them for helping. She then begins stripping down, which Mitsuba expresses concern. Shinoa then tells a still hesitant Mitsuba that Ferid had the bath and food prepared for them ahead of time, and even has spare uniforms, which has Shinoa conclude that Ferid has connections to the Imperial Demon Army and is all going according to his plan. While examining bras, Shinoa jokes about Mitsuba's big breasts, but becomes flustered and uses Shikama to open the front of Mitsuba's shirt when Mitsuba discovers her breast size.
Shinoa and Mitsuba are afterwards seen having ice cream, which Shinoa claims that having dessert boosts girl power. This causes the boys to look at Makoto, who is also having ice cream. Shinoa then watches as Yu talks with Mika. When Crowley tells everyone its time to go into the basement, she asks what's down there, which the vampire tells them that there are bodies down there. Shinoa expresses concern for Yu going berserk and damaging the bodies, and watches as he has Yoichi bring out Akane's head for him to carry so he won't do that.
The squad then proceed down into the basement, Shinoa looks at and walks from Makoto observing Shusaku to Crowley looking at one of the corpses. She asks if he knew the person and if he is looking to bring them back, and after he answers her, Shinoa then asks about the means to control the seraph within Yu. Crowley points to a stack of books on a table, and upon seeing the crest of the Demon Army on one of the books, Shinoa tells him that the research materials are dense and complex, which would take them time to understand these readings. When he tells her that an old friend is supposed to be helping them, Shinoa asks who that would be.
Everyone hears a loud roar upstairs, and Shinoa asks Crowley if the person who is supposed to help them has arrived. They then hear a person coming down the stairs, and its revealed to be Guren. Shinoa decides to stand back and watch as the others come up to Guren, unaware of Mahiru talking to her. During Guren's explanation to everyone about Kureto and Mahiru's struggle to become the head of the Hīragi family, Shinoa claims to have escaped the sibling power struggle which Guren doubts as he reveals to her that she was born with a demon inside her and asks what Shikama whispers in her ear. Shinoa then asks Guren to clarify what the chosen Hīragi is fighting against which Guren says is the utter hopelessness staring her in the face. At some point, Shinoa and Yu sense something except Shinoa feels a sudden pain in her chest.
Going along with Guren's plan to resurrect the people that were killed by the Apocalypse virus, Shinoa, Kimizuki, and Makoto struggle to understand the research books in the basement until a sudden disturbance has them rushing outside to find Yu briefly passed out in his attempt to control the seraph. At some point, she and the members of her squad and Guren's listen to Guren's plan in rescuing Krul and Ferid from Ky Luc.
Three days later, when Ky throws a piece of Ferid's body at Yu, Sinoa and Mitsuba block the projectile. The squads are successful in rescuing Ferid, and while the disembodied vampire was putting himself back together, Ferid uses his nakedness to freak out Shinoa and Mitsuba.
Shinoa and the others then go to Guren's old home in Nagoya, and then comes down into the basement with her squad and Guren Squad to see Guren, Mika, Ferid, and Crowley already there while Yu is inside a barrier to confront an imprisoned seraph. Shinoa attempts to go through the barrier, but is warned by Guren not to do so. She and the others then go after Yu when he and the seraph get outside. Upon catching up with him and hearing Yu tell Kimizuki to use the drug he has been using on the seraph, Shinoa stays behind with the others as a backup so Kimizuki and Guren can get to Yu.
As everyone is fighting, Shinoa is watching Yu fight and wonders how he can easily care for the well being of others compared to herself having no raging passions nor welling emotions. It is here that she gets interrupted from her musings by her demon, Shikama Dōji, when he tells her that she has desires like lust. Now within her own mind, Shinoa is told by Shikama that she is of age to desire love. When asked to be reminded how old she is, Shinoa tells him that she is 16, and when Shikama brings up that she was the same age as Shinoa when she slept with Guren, Shinoa says she doesn't compare herself to her older sister.
A closed door then appears on the floor in front of her, and when told by Shikama that she is able to build thick walls to keep her emotions at bay, Shinoa responds that those thick walls are to keep the demon from coming into her heart. When questioned what a human is without passion, Shinoa answers, "Peace" which has Shikama say she is lying as she wants to experience love and it's for Yu. When Shikama tries to open the door, Shinoa blocks it with her foot with a command for him to close it. She then has the demon wrapped up in chains and restrained which also silences his claims of her one day losing control of her desires.
With her cursed gear in hand, Shinoa returns to the battlefield. She then looks back up at Yu, saying that it's fascinating that his only desire to live is so that he can save his family and wants to learn more from him on more reasons to live. With the Horsemen vanishing, Shinoa comes up to Yu and Kimizuki complementing their success in curing the seraph, but her smile becomes a frown when her heart gave a pronounced beat.
As Shinoa's and Guren's squads arrive at Shibuya, they are attacked by the city guards of the JIDA but Yu defeats them. Saying this wasn't how they are supposed to return. After asking Guren about how do they proceed Ferid interrupts him, she then further says she didn't anticipate arriving with a bad situation. She tells Mitsuba that her sister Aoi is there as well, after Yu says the Hiiragi's were the ones who betrayed them, before Aoi could signal the other soldier to attack, Shinoa and Narumi silences him. When Mika says finding a reason to live in this world is difficult, Shinoa tells him that the Hiiragi's have been like that for centuries. After Kureto calls them, only Guren, Shinya and Shinoa are permitted to enter, as they enter Shikama Doji stares at the three of them.
In Kureto's room, Shikama Doji manifests into his scythe form willingly, surprising Shinoa much to Guren and Kureto annoyance. She later talks to him in private inside her mind, and he appears in scythe form instead of his actual appearance. Shinoa hears that he won't be able to show his true appearance anymore until she opens her heart to him, to which she refuses saying that he will possess her but Shikama Doji explains that he is much too busy possessing someone else. Shinoa is tempted to lower her barriers against him saying that she should be fine no matter what as she has no desires but Shikama Doji though she denies it. She is even offered some of his memories that could save Kureto but she counters saying her life is more important.
Shikama Doji tells her that she might be able to turn Mika back to human if she accepts him into her heart as she wonders about the happiness and what the look will be on her beloved's face. She is further enticed as Shikama suggests a way to return Yu's humanity back to him, to which Shinoa's heart starts pounding louder. Shikama Doji tells her that the demon and angel within Yu will eventually erode away his mind. She tells to stop calling him a demon to which Shikama Doji states he is not a demon and will reveal who he is if she lowers her walls. Shikama Doji states that she truly wants to save Yu and declares that he will eventually possess her instead of Kureto, affirming that there has never been a vessel of her caliber in all the generations of the Hiragi Family. Shinoa starts to scream to Shikama Doji in anger to be quiet telling him to shut up repeatedly.
Shinoa wakes up and finds herself in a hospital bed next to Guren, who tells that she was moaning while sleeping, and is told she fainted in front of Kureto also those who broke the Hiragi's blood remains three of them including her, Kureto and Seishiro. Guren says that now Tenri is dead and the monster is still on the move it might have affected her being a Hiragi herself, she tells Guren that she might be examined for her safety, she thinks now that she is an expandable subject to be experimented on to save Kureto and simply says that her scythe was having a bit of tantrum, Guren wonders if it has anything to do with Kureto condition. Shinoa says it should be examined as well since the being that is currently possessing her brother is trying to possess her to, she assumes that it went after her sister Mahiru before she was born saying that it was to protect her from that thing that her sister gave up her life. Mahiru-no-Yo manifests next to her smiling, and is told by Guren to sleep not guaranteeing that it would help. She teases Guren saying that it is her fault he wasn't able to be with Mahiru all the time despite their love, Guren tells her what happened in the past is gone and doesn't matter, what's more important is the current situation. Guren leaves the room however Mahiru-no-Yo stays manifested next to Shinoa whom she cannot see.
Still, in the laboratory, Yu visits Shinoa whom he is worried about her condition about her possessed by a monster, which she denies but Yu insists he will save her and grabs her shoulder. She notes to herself this is bad since being with him increase her desires, lowering her internal walls. She tells Yu that Shikama Doji visited his demon and after few attempts, he assimilated with Asuramaru, she tells him to go save him.
Knowing that Yu is in contact with Shikama Doji, she tries to stop him from talking to him and begs for help as she is aware it will possess him but Yu doesn't respond. Guren hears her and she explains the situation, saying the monster inside her moved to Yu. She managed to enter Yu's mind by opening a pair of doors saving both Yu and Asuramaru from being killed by Shikama Doji and throws her scythe at Shikama Doji saying it's the first time he's been wounded complementing her. Shikama Doji reveals to Yu that Shinoa is in love with Yu, all the more reason she came to rescue him even though she knew that was the one thing she absolutely shouldn't do that, after 16 years she finally lowered her inner walls in her heart. Shikama Doji leaves both Yu and Asuramaru stating that he completed his goal for today. He returns to Shinoa's side, grabs her by the neck, she starts losing consciousness but manages to resist him with a little courage from Yu saying she might try a little harder, however, she, unfortunately, doesn't have the strength to resist him and apologizes to Yu saying he is noisy when he tries to save her and she could hurt him.
A door opens and Shikama Doji takes Shinoa with him then closes it preventing Yu from saving her. In the real world, she is lying on a stretcher with her squad on her side and Guren announces that her heart isn't beating shocking everyone. Her eyes look dead as if she is in a coma and a worried Yu looking for anyone to save her. Meanwhile, her eyes begin to change color, Mika notices this and announces that she's transforming into a vampire.
Shinoa experiences her body feeling strange as she is transforming into a vampire, she is taken to the laboratory by orders from Kureto. The researchers try to save her but they are approached by Ferid and Crowley. Conscious and sweating, she listens as Ferid mentions a way to prevent her transformation to a vampire is by killing her. As Ferid swings his sword to kill Shinoa, Shikama Doji manifests in scythe form and cuts Ferid's abdomen bisecting him then slices Ferid's arm off before Crowley saves him by throwing him away. Shikima continues to attack Crowley who manages to defend himself but then abruptly slices off his head. Shinoa is raised upright on the stretcher and is asked by Ferid if they are the First Progenitor to which she replies what if she is, and then listens as Ferid asks her questions. Shikama Doji sees no point in telling him what the point is, but does say he is not the one who made him immortal. Hearing about Rigr Stafford, Shinoa who is possessed asks if he is the cause of this ripple effect.
With Kureto, Guren and Shinya having repressed Mika after he thought they were puppets, Shinoa comes to investigate. Clutching what remains of Ferid she appears very happy with herself. However, Shinoa who is possessed by Shikama Doji attacks the group, summoning multiple scythes. The scythes continue attacking the group whom they defend against. Upon hearing the Hyakuya Sect are outside the walls, Shinoa concludes that Rigr has come and leaves the group by smashing her way out the window. Shinoa later arrive in the lab where they keep the Seraph of the End and greets Saito knowing it's the first in Shona's body, as he says it's been a while which she answers it has been some time addressing him as Rigr.
Their conversation moves on as Shinoa asks Saito how many years has it been which he answers it has been at least 2,000 years or so and further asks him if he has been well, which he says he has as the years have been entertaining for him. When Basteya and another Hyakuya soldier appear behind Shinoa, she is intrigued what will he do, to which Saito answers by restraining her. She laughs it off seeing how weak they are. Shinoa has her arm bound with one of Saito's chains as she reaches towards Mirai but she easily breaks free by using her hand cutting off his head.
After his head which is chained has been cut off, she comments on Kimizuki taking Mirai that if they join Saito they will be his guinea pigs rather than hers, then wonders what happened to him as she does not remember constructing him like that. After asking if he would die by cutting off his chain that is attached to his head that he would die, Saito pleads her not to as he would die, but she slices it up nevertheless and several chains sprout out of his head and begin attacking her and tells him that he lied to her about not dying.
She jumps out of the building and Shinoa uses the seraph wings of Shikama Doji to avoid falling by flying in the air. Saito comes out as well and summons beasts which Shinoa comments on resembling a beast of the apocalypse. Saito comments on her wings as well by saying how lovely they are just like an angel, she tells him how ironic is it as she has these wings despite losing the sun forever and falling into darkness all because a simple taboo. She further tells him if he keeps interrupting her much more she will have to punish him. She summons multiple scythes around her wings and Saito orders numerous chains and his beasts to pierce Shinoa through and Shinoa attacks with her scythes to slice him to bits. The collision between the two causes massive explosions around the area.
As both of them clash in the air, Shinoa's scythes and Saito chains weapons reach down to Shinya's group whom they barely managed to dodge the scythes and chains, causing tremendous damage that crashing into few buildings. Later Shinoa reacts to Noya awakening and remarking that it seems something happened, the first questions Saito if he is responsible.
They notice their development in their battle, Shinoa forms an enormous scythe and they know Saito wouldn't challenge them using a trump card, noting that he wasn't foolish even back two-thousand years ago. Wanting to end the battle without him using any tricks or trump cards, they throw the scythe at Saito. Some time later, Guren arrive at the battle between the two, they don't take it seriously when questioning Saito that if this is his trump card but answering with silence. They send scythes at Guren to kill him but are halted by both Mahiru and Noya. They are surprised when Guren has an evil key in his possession which they call it a sinful key, however they are calm that one isn't enough to stop him, but Saito counters by three of them can seal Shikama Doji away considering that he is yet to manifest his real body. Guren attacks them but Shikama Doji is still calm that it isn't nearly enough and considering that their speed is superior to his, however Saito betrays Guren to bite him wanting to take away his demonic powers only to be misled by Guren deception when he calls Ferid who uses Jigenso to teleport next to Saito and stab him with his own evil key. Directly after that, thanks to Jigenso, Guren, Mahiru and Noya all acquire an evil key. Then they surround them and with a sinister power trapping Shinoa. 
With Shinoa’s body under the threat of breaking from the effects of the sinful keys, she is relinquished from Shikama Doi’s possession and she falls to the ground. Landing in the arms of Mahiru, she responds to her recognising her as her elder sister. Safely reaching the ground, he notices Guren's transformation and asks if he has turned into a demon. With him bounding away without a response, Shinoa wonders about Yu.
Shinoa awakens and gazes on the blue sky, unable to move, complaining that her body hurts. Though she forces herself to sit up, noticing all damage and the burning buildings she wonders if she is the cause of all that. Mitsuba comes running to her, and she is hugged tightly causing her to feel pain. Shinoa is informed by Mitsuba about Yu's kidnapping by the Hyakuya Sect. After some bickering and jokes with each other, Shinoa is thinking to whom they should side with before spotting Yoichi who is carrying an unconscious Kimizuki with his deceased sister. Shinoa is shocked when Yoichi informs her that Guren killed her. After some thinking to which who should they side with again, she orders Yoichi and Mitsuba that rescuing Yu is their top priority.
In the back of the jeep that Kimizuki is driving, Shinoa answers Mitsuba that Yu is probably over in the direction where the Lt. Colonel went. With her scythe drawn, Shinoa fully supports them heading to save Yu who has been spotted.
Powers and Abilities
As a member of the Hīragi Family, Shinoa proves herself qualified to handle a weapon of the Black Demon Series as seen when Guren engulfed the classroom with his Cursed Gear's aura, albeit the weapon she wields is a lower class. As leader of her squad, Shinoa remains levelheaded and takes an analytical approach at dire situations. She is knowledgeable about weapons, demons, seraphs, and vampires as well as the Demon Army politics. Her natural abilities include physical abilities, and mental abilities, such as having strong resistance to opponents. According to Shikama Doji, she is the first person to actually wound him by throwing her scythe at him despite being an immortal being.
In the Light Novels, Shinoa is naturally and highly skilled at martial arts, and is also skillful in using magic, and Guren once mentioned that she's an incredibly gifted child that looks like a genius. Using her sturdy build and physical strength, Shinoa proves to have the physical abilities to take down multiple vampires at once. Even before acquiring her scythe, in the Light Novels, Shinoa's martial arts skills is more than enough to kick and take down vampires and humans possessed by demons. Minus using her legs, she additionally is shown being able to wield her scythe extremely well despite her young age, like when she was able to deflect several bullets at once when protecting Goshi. Moreover, Shinoa has the need to protect everyone, despite everyone counting on her or Yu to protect them. She proves this very well. Shinoa is a very strong girl and Guren states that she has the strength that surpasses him, despite having any sort of formal training.
Shinoa is also shown to have a strong range in battle, she can jump very far and sprint very fast. She has good strength in her arms, and legs for tough kicking skills. Her arm muscles are used for punching, as well as carrying and use for her scythe. When possessed, she occasionally uses her fingertips to cut off one's head with a single swift with her hand or her fingertips. Shinoa does have high agility, which causes her to jump and move easily, jumping over fences and walls way taller than her.
- Strong resistance to demons: Shikama Dōji has said that Shinoa is the perfect product of the experiments, and that she is able to resist any demons that she comes in contact with. This is due to the fact that she doesn't have a lot of desires in her heart. Shikama Doji also mentions that Shinoa can contract to any number of demons without being possessed. Shinoa is still unaware of this. As of eight years later, Shikama Dōji stated that in hundreds of years of possessing the Hīragi family, there has never been a vessel of her caliber, noting that there would be no need for him possessing Kureto any longer once he starts possessing Shinoa. Which the latter succeeds in doing so. After he leaves her body (whom she was possessed for a while), she wasn't affected in any way and immediately recovered normally without any harm to her body.
- Shikama Dōji possession: After Shikama Doji possessed Shinoa, her strength increased tremendously, overpowering and defeating Ferid effortlessly. Shinoa has also shown the ability to summon and materialize multiple scythes to attack. In addition her agility has increased as she can jump through high building's windows and smash them, and is able to dodge Saito's multiple chain attacks. She also has gained the ability to have the angelic wings of Shikama Doji for flight, and materialize numerous and enormous ethereal scythes around her wings that whirls around similar to a halo of scythes becoming a deadly attack. She usually cut off one's head with a single swift with her hand or her fingertips.
- LN exclusive: Shinoa is seen to be skilled with talismans as Guren noted her as an exceptionally gifted child, her talents befitting of her family name.
- Shikama Dōji (四鎌童子 Shikama Dōji?, lit. "Four-Scythe Child"): A manifestation-type demon weapon from an unknown series. Shinoa takes out a pen-length black rod and spins it, which then transforms into a black massive scythe with a thick, black aura around it. She can call out the demon, which she fondly addresses as "Shi", inhabiting it out of the weapon to attack an enemy. It is strongest at mid-range. Her primary ability is to detect anything that comes within the attack radius of her scythe.
- "I guess I can’t expect you to take my word for it. Maybe if I tell you some of what I know? About the Brotherhood of a Thousand Nights? And the cursed weapons? The fact that my sister sold out the Hīragis in pursuit of power, all for the sake of some boy she loves? Well? Is any of this starting to sound familiar?"— To Guren, Chapter 2, Page 216
- "OK! Shut up, shut up, shut up!"— To Mika
- "I’m just a kid. To be honest, power and influence just seem boring to me. I was lucky enough to be born with a powerful sister, so I don’t have to deal with the same expectations over leading the clan. That’s between Kureto and my sister. I’ve had some training from the clan, mostly just as a backup in case both Kureto and Mahiru die. I’m still fairly capable, though. At least, for my age."— Chapter 2, Pages 216-217
- "I’m just trying to prove whose side I’m on. I’m not interested in the Hiragis. Or the Brotherhood of a Thousand Nights. But I love my sister… She’s always been kind to me. And interesting. She tells me everything."— Chapter 2, Page 217
- "Don’t go to the Hyakuya Orphanage. Mahiru is planning to betray the Thousand Nights, too."— Chapter 2, Page 217
- "It caught me by surprise, to be honest. Apparently, my sister loves you so much that she’s willing to leak important information for you. I don’t think I’ve ever seen her act this way before. She’s usually very rational and logical. I guess love makes people act impulsively. I don’t quite understand it. But then again, I’m just a kid."— Chapter 2, Page 218
- "Hmph… I really don’t understand grown-up love. It all seems a bit twisted to me."— Chapter 2, Page 219
- "Not another torturer, I haven’t done anything wrong, so maybe you should just let me go already."— To Guren, Kureto, and Aoi, Chapter 4
- "No, I’m not hurt. Just as you planned, I’m sure… But I think my maidenhood was in danger for a while. I’m only eight, you know."— To Mahiru about Kureto threatening to have her raped, Chapter 4
- Note: She is counting her age using the Japanese system, where they grow a year at New Year's rather than on their birthdays. Using the English system, she is still seven years old until her birthday on Christmas.
- "Nope, it’s just makeup. I look like a zombie, don’t I? Rawwrr!"— To Shinya with her torture makeup, Chapter 4
- "Don’t ask me. I’m just a kid. All that adult boy-girl stuff is still a mystery to me."— To Shinya about Mahiru loving Guren, Chapter 4
- "Even after what happened, I think she’s still the one person in the world who would be most upset if I were to die. If I wound up dead in some gutter someday, I don’t think there’s anyone else who would really care."— To Guren about Mahiru abandoning her, Chapter 4
- "Well, that’s a shocker! Considering how little we know each other, I would’ve never thought the two of you would feel sad if I croaked. I guess that goes to show how much you both love my sister. You even care about me just because I’m related to her."— To Guren and Shinya, Chapter 4
- "Unfortunately, it looks like my sister is through with all of us—me, you, and Shinya. She made it pretty clear today that she’s abandoned us. I don’t think she’ll make contact again. She’s already accomplished whatever it is she wanted to accomplish at this school."— To Guren and Shinya, Chapter 4
- "Count me out. All you adults with your grumpy faces and your stupid wars are boring me. I’m going home."— To Guren, Chapter 4
- "You weren’t thinking about sneaking into a pretty girl’s room to do nasty things to her in the dark, were you? No thanks, you perv. I might have to tell my sister on you."— To Guren, Chapter 1
- "Maybe you can’t tell just by looking, but you know I’m actually an excellent chef? …My skill at pressing buttons on a microwave is unparalleled."— To Guren, Chapter 1
- "The only calls I ever receive on this phone, by the way, are from wrong numbers, telemarketers, and my sister."— To Guren, Chapter 1
- "Holy shit, Superman!"— To Guren after he rescues a parent and child by using Noya, Chapter 3
- "Mind knocking next time?"— To Guren after he enters her apartment without warning, Chapter 4
- "Wait, the world is ending?"— To Guren, Chapter 4
- Four 「四」 can be read as "Shi" 「し」. Shi 「死, し or シ」 means "Death."
- Hīragi 「柊」 literally means "Holly."
- She usually calls Yūichirō by the nickname "Yu-san" (優さん Yū-san?) in Japanese.
- According to the light novel, she and her sister Mahiru were born as part-demons.
- She can't cook.
- Shinoa is the youngest and shortest member of her squad.
- From the Osaka Arc, she is sixteen years old.
- According to the TV Anime 108 Fanbook:
- She does not have a favorite color.
- To her, a person that gets bullied easily is Mitsu.
- According to the Manga 8.5 Fanbook:
- She likes Pocky.
- Interests/Likes: Originally had no interests, but lately has been thinking about her comrades/ Yu / Methods to increase her bust size.
- Favorite food: Food with cheese / Mont Blanc.
- What she looks for in the opposite sex: A prince on a white horse, of course. Oh, but what kind of person is this Prince Charming? He came from The Little Red Riding Hood, right?
- In the popularity poll, Shinoa earned 2nd place with 4,074 points. In the 2019 popularity poll, Shinoa is ranked at 5th place with 2,793 votes.
- She loves embracing people.
- She is too short to drive.
- Shinoa gets teased/mocked for her height.
- According to Shikama Doji, she's way stronger than her older sister Mahiru and Kureto. Mahiru herself acknowledged this.