Mahiru Hīragi

Mahiru Hīragi (柊 真昼) is a central character in Seraph of the End, particularly in the prequel Seraph of the End: Guren Ichinose: Catastrophe at Sixteen light novel series, and its manga adaption. She is the older half-sister of Shinoa Hīragi, and was romantically attracted to Guren Ichinose. From the prestigious Hīragi Family, she was next in line to become head of the clan on account of her capabilities and intellect.

Taking matters into her own hands, Mahiru would seek out vampires to become one herself. Betrayals abound as Mahiru maneuvers her way against organizations from her own family's, to the Hyakuya Sect. As a namanari, she eventually turned into a demon, and willingly fused herself with Noya. Shortly before the anticipated catastrophe occurred, upon being sealed within Guren's sword, she became a Cursed Gear weapon, a part of a single entity called Mahiru-no-Yo.

She is referred to in the Owari no Seraph manga, as well as the Seraph of the End anime. Later Mahiru is separated from Noya, but is still a demon active as a Cursed Gear, with a physical body. Along with Guren, they resume their plan, supposedly against the first progenitor, Shikama Dōji, which involves Yūichirō Hyakuya and Mikaela Hyakuya.

Appearance
She is described as a beautiful young girl, with long ashen hair with short sidelocks, and amber eyes. A comment from Shinoa is that Mahiru as her half-sister is taller and way more voluptuous than herself. When she was a namanari, Mahiru displayed no distinct physical features that showed the demon was in control, except for a red glint in her pupils that rarely showed. After becoming a vampire, Mahiru develops their physical distinguishing traits such as her eyes becoming red, where she additionally grew fangs.

For clothing, Mahiru is usually seen with the First Shibuya High School uniform. This is a, which consists of a blouse with red trim around the collar, with a grayish blue sailor-style collar which also has red trim. She wears a similarly colored skirt with a belt. A red uniform ribbon which is thinner than normal sailor fuku is attached to the bottom right end of the collar. The school's emblem is located on the right of her chest. Mahiru wears thigh length grayish blue stockings, and dark blue dress shoes along with them.

Human
A very popular member of the prestigious Hīragi Family, ahd was famous for treating the other clans with kindness and equality. She is remembered as being gentle, sweet, and charming. On one occasion, Mahiru shared a cake with Guren, and showed concern over the bruises he received from his brutal training. Also shown to bow down to the pressure of her family, Mahiru would hide and refused to meet Guren when her family sent two people to interrogate him. Aside from that, Mahiru was charmed by him greatly and spoke fondly of Guren.

Her great intelligence and skill made her father favor her, but she hated the Hīragi Family. Perhaps as a consequence. Mahiru appeared to be less cold-blooded and ruthless than her half-brothers. She intervened to save Sayuri when Seishirō was beating her and attempted to strip her as she did not like picking on others. Noted as a perfectionist,, this more likely stemmed from Mahiru having many expectations on her while doing battle with the demon born inside her. Appearing to value human life more than her family, this was displayed in her desperation to save Shinoa, who also had a demon inside her. Ultimately, Mahiru took Shinoa's demon and sacrificed the rest of her humanity for her half-sister.

"Ahaha. Once I began acquiring power, I enjoyed the feeling. You understand, don’t you, Guren? You’ve grown so strong, but you’re still flesh and blood. You must feel the seductive pull of power… There’s a limit to flesh and blood, though, isn’t there? To become truly powerful, you have to be willing to transcend to the next level."

- Speaking to Guren on how she feels regarding the acquisition of power.

Not shying away from experimentation, especially not on herself, Mahiru was peppy when it came to such matters. Greeting scientists, Mahiru was eager for them to carry out some successful experiments. A similar enthusiasm was shown when sparring with Kureto Hīragi, who she proceeded to sit on satisfactorily upon defeating him. The determination would be applied regardless of who was hurt, Mahiru would strike Shinoa to prevent feelings that the demon could exploit should they develop.

What is left of Mahiru's human side is often seen wrestling for control with her demonic side. Whenever Guren is injured, such as when he sliced off his own arm to stop the spread of the demon's curse, Mahiru's human side is able to resurface briefly. Crying, she urgently tries to reattach Guren's arm. At times warning Guren to not to be fooled by what her demon side says, Mahiru expresses deep remorse and guilt over what she put him through. She also hated herself for doing it, and would go as far as to request to be killed by Guren.

Namanari
The demonic side of her gradually takes more and more time in control of her body. Its influence results in Mahiru twisting her love for Guren by starting his transgression into demon hood as well. Her need for power to protect and be with Guren warps into a desire to either rule or destroy the world.

"My loyalties lie deep in the heart, where madness and depravity live. As do yours. Don’t they, Guren? But it’s not enough. You need to sink to the same depths as I have. Why didn’t you kill that girl from the Jūjō Clan a moment ago? Or that fool from the Goshi Clan? It’s what you should have done. You need more hate, more madness. Let it rush through your body, Guren, let it consume. Demons thrive on the hopes of man. In order for a demon to choose you—"

- Drastic ideas to Guren, before her personality would change to discourage him.

Mahiru-no-Yo laughs often and loves to mock Kureto along with others. She has no sympathy or compassion for anyone and is willing to ruthlessly kill anyone who stands in her path and is even cruel to them. Among the very few features that remained of her previous self was her love for Guren but even then, she is not above being unkind and be willing to harm him. Her love is also twisted so that while she will not kill Guren, she is absolutely delighted when Guren shows his strength. Fond of touch, she wants him to give in to his demon and join her. She is, however, not above showing other dark emotions whenever Guren is involved, a cold rage is shown when Guren coldly said he didn't gain power just to be with her. A strong sense of jealousy towards the girls who love Guren despite knowing how he would never fall for them as he only loves her means she acts particularly cruelly due to this. Resentment is also show towards Guren's other friends, where she wants him to kill all of them. There is bitterness when referring to how Guren wanted to protect both her and them. Along with that, she maintains contact with Shinoa, seeming to indicate she retains her care for her. Since the human and demonic personalities are in flux, they can be seen arguing and fighting for control when the demon puts Guren in danger.

Vampire
Her personalities no longer fluctuate, and Mahiru expresses both the haughty playfulness of her demon side and the hopeless love of her human one. now consumed by lust for blood, especially Guren's, Mahiru enjoys feasting on people's blood and drinking them dry. She also enjoys battles and manipulating others to do her will.

"True. I wanted to be born a normal girl, and do normal things like fall in love... It really is unfair."

- Sharing her desires to Kureto when he calls her unfair for being strong.

Her human personality seems to be about as strong as her demon one, however, which manifested in her showing love for Guren and care for Shinoa as well as being much more easily angered and jealous. She gave her sister Shikama Dōji to make sure she can survive the end of the world, and spared Guren despite having him at her mercy along with actually trying to protect him from her malicious experiments. While Mahiru's love for Guren made her not kill him while she murdered all of his friends, this was not granted to his female friends, who cared for Guren in front of her, much to her rage. For her fiancé making the mistake of mocking her love for Guren, she afforded him a particularly painful death. Although she slaughtered all of them ruthlessly, at the same time Mahiru willingly told Guren how to resurrect his friends as she died. She was also genuinely touched to the point of tears as Guren proclaimed his undying desire to save her. As she died, Mahiru revealed all she wanted was to have a normal life with him.

Demon
An independent demon separate from Noya, like herself as a human Mahiru is consistently carefree and joyful. Quick to act, Mahiru thinks nothing of seizing one of Shikama Doji's scythes, and reacts fast to use the Sinful Key she acquires against him. Catching Shinoa, she ensures her sister does not fall. Finding Mika, Mahiru drily answers him that rescuing Yu is out of the question.

"What, me? I'm everybody's favorite lovely idol, Mahiru!"

- Happily introducing herself to Mika.

Then remembering what she is supposed to do, Mahiru fights Mika. When spell tags are used, Mahiru manically laughs as the explosions occur. Floating down to Yu, she questions whether he remembers her, where she has memories of him. Particularly in tense situations such a major fights, Mahiru indulges a mischievous sense of humor.

"Ooh! Ooh! You want me inside you? Ohmigosh, Guren. You are sooo lewd."

- Her reaction to being told to get back inside Guren.

For all her planning, Mahiru is unsure how to act when Yu hears Mika's voice, unaware of whether it is a plot by Shikama Doji. It is also news to her that he may have planned for her to have all the black demons together. Considering both, Mahiru leaves their plan to Guren. Investigative, Mahiru seems to have infiltrated a memory that Mika was accessing, and apparently motioned to him that she was present. Curious as to whether she was seen, Mahiru would also like to know how long Yu has been around for.

History
Mahiru was conceived through artificial insemination using the seed of Tenri Hīragi in demon-possessed women, which lead to her being born in 1996 with a demon inside of her. Eventually, when Mahiru was six years old, the Hīragis had her mother killed, so she attempted to anger them by becoming close to the Ichinose Clan, where she encountered Guren Ichinose. Shortly afterward, the two fell in love until they were violently separated for the next ten years. Three years since Mahiru's separation from Guren, her half-sister, Shinoa Hīragi, was conceived through the same demon experimentation and was born with her own demon inside her. At some point (or even earlier), Mahiru began having nightmares where the demon spoke to her from the shadows, and its voice would get louder as she continued to grow. When she learned that Shinoa was also having the same dreams as her, Mahiru tells her to not tell anyone or they would be used as experiments again.

The following year, the Hīragis selected and adopted Shinya to be Mahiru's potential mate to keep their bloodline strong, despite both of them being ten years old. Mahiru oversaw some part of Shinya's training against other candidates, a scenario she may not guess would be viewed by Byakkomaru.

Upon meeting Shinya face to face for the first time, Mahiru tells him she would not fall in love with him as she already had someone; however, if she openly stated to her family she did not want him, they would have disposed of him. Where Mahiru still wanted to be with Guren, she and Shinya agreed that he would be her cover-up fiancé until she could be with the person she loved. When Mahiru entered puberty, she continually blacked out and would lose herself to desire on account of the the demon's strengthening influence. Not wanting Shinoa to end up with the same fate, Mahiru revived the demon curse experiments and joined the Brotherhood of a Thousand Nights to aid her in exchange for giving them information on the Hīragis. Thus, Mahiru began her research and development on Cursed Gear, and would use herself as a guinea pig to test the power of the demon weapons.

At some point, through some means, Mahiru somehow extracted the demon from Shinoa and took it into herself, which sped up her transformation into a demon. As well as turning into a demon, Mahiru saw visions of the future and even prophesied the end of the world on Christmas Day 2012 as God's punishment against human ambition for meddling with the taboo.

Events of 2012
Ten years after separation, Mahiru and Guren would cross paths again at First Shibuya High School when she delivered the freshmen address. At the school, Mahiru and her brothers are the most popular and respected by the student body due to their power and family status. After Shinya puts Guren in the nurse's office, Mahiru comes to visit him and reconnect after many years. Treated coldly, Mahiru is mockingly congratulated her for being betrothed to Shinya, leaving her hurt and frustrated over Guren's change in temperament.

During the qualification exams, she saves Sayuri when Seishirō severely beats and humiliates her, but coldly tells Guren she refuses his gratitude. Of the view he is weak for not fighting for her anymore, Mahiru leaves with a dark expression on her face, but not before she hears Guren tell his attendee they did well as if to mock her, leaving Mahiru further disappointed.

Sometime later, the Brotherhood of a Thousand Nights attacks and kills many students and teachers. While fighting Saitō, it is mentioned that Mahiru betrayed the Hīragi Family by joining with the Thousand Nights. Mahiru then appears herself when Guren states that he is not gaining power just for her. Mentioning for Guren to not say such a thing when he doesn't mean them with cold anger, unleashing a strong killing intent, Mahiru attacks Guren with a black katana. Although Guren is able to successfully fight her off with his stronger sword skills, Mahiru's own fighting prowess and her superior physical abilities slowly overwhelms Guren.

Then revealing that her sword is a cursed gear, a demon-possessed weapon that she and the Thousand Nights were able to successfully create, with the combination of the Thousand Nights and Hīragi magic, they were even able to make contracts to bind high-ranking demons. While attempting to convince Guren to join her, Mahiru suddenly stops mid-sentence and becomes pained. She is able to articulate to Guren that the demon has possessed her and that the cursed gear experiment is actually a failure, before denying that there's anything wrong.

The sword then begins affecting her right arm, before Mahiru is prompted by Saitō that they need to go. When Guren lunges at Saitō in anger, Mahiru intercepts his blade which cuts his sword, Kujakumaru, in half. Mahiru gives Guren one last chance to come with her, yet she is refused as his quest for power is different from hers. Then informing him about the apocalypse to take place on Christmas, Mahiru states they will meet again when the world comes to an end. Before taking her leave, Mahiru shares with Guren that she loves him and promises that she will be waiting for him when he needs her again.

"…I want to tell you something important, Guren. The truth is, this year at Christmas, the world will come to an end. The trumpets of the apocalypse will sound, and a virus will spread. When that time comes, a new world will arise. One that, more so than ever, requires power. When that time comes, I know you’ll need me once more… We’ll meet again, Guren, when the world comes to an end."

- Revealing when the world will end, and preparing for it.

During their investigation of Ueno Zoo, Guren Squad battles a tiger-like creature that was made with genes from the Horsemen of the Apocalypse. When the squad was about to retreat after due to Guren's wound, Mahiru turns up and knocks Mito, Norito, Sayuri, and Shigure unconscious within moments. The initial strike on Shinya was avoided before Mahiru was able to grab him by the neck and choke him to unconsciousness. Divulging to Guren that she plans on betraying the Thousand Nights as her loyalties lie wherever there is power, when asked where that power is, Mahiru says that it is in depravity and madness which lives deep in the heart. Mahiru advises Guren to follow that path as well.

Thrusting the black katana into the ground, Mahiru demonstrates how its curse can affect Guren. Encouraging him to take the sword to slay the chimera, Mahiru then steps back to watch. When Guren reaches for the sword, Mahiru suddenly cries out to him to stop and not lose his humanity, before telling herself to be silent and hitting herself in the chest. Questioned which one is the real her, Mahiru answers if it had anything to do with his choice.

After Guren takes the cursed gear, which causes a demon to sprout inside him, Mahiru becomes ecstatic when he makes quick work of the chimera and goads him into killing his friends and joining her. When Guren was about to do just that, his other hand used his sword, Hoarfrost, to severe the lower part of this arm that was holding the demon blade, consequently Mahiru quickly gets that limb and holds it tightly to his arm so the demon's regenerative ability can reattach the limb. In desperation, Mahiru becomes tearful when the regeneration process fails to work fast enough. While Guren tries to convince her that there could be another way, Mahiru is also asked to stop this cursed gear research, only for her to reject him and getting her offer rejected in return. During their talk, after Guren's arm has fully reattached itself, Mahiru confirms that the demon has tainted a part of his soul and promises that he will fall just like her.

Rushing over to claim one half of the chimera's corpse, Mahiru notices that a well-dressed vampire is also there. She immediately attacks him, but even with the demon's power, the vampire is able to withstand her Cursed Gear. Mahiru identifies him as a vampire noble, and hears this confirmed where Seventh Progenitor Ferid Bathory introduces himself. Defeated along with Guren after Ferid resumes their fight, the other half of the chimera is taken with Ferid. When Mahiru demands to know what he is doing here, she hears Ferid answer that he is investigating what he has heard about humans researching the forbidden. Knowing that she stands no chance against the vampire, Mahiru sheathes her sword and speaks to Guren that the Cursed Gear can become even more powerful, but she does not have enough time to explain. Reminding Guren that he will fall like her, Mahiru picks up the other half of the chimera just as a Thousand Nights helicopter arrives.

When she was warning Guren to leave, Mahiru notices dozens of Fuda were placed on the ground to form a barrier and realized that Shinya was awake the whole time when she was revealing her intentions to Guren. Lunged at by Guren, while Shinya uses the Fuda to retrain ensnare her legs, Mahiru breaks through them with ease as she evades the entrapment. Further surprised at the true purpose, Mahiru finds Guren has sliced off a piece of the chimera. Although Mahiru says cannot allow the Hīragis to have the chimera, she allows Guren to take it once he promises it will not be going to them, and because she herself is betraying both sides. Hearing Guren promise that he will be catching up to her, Mahiru tells him that she will be waiting before leaving.

Later, when Kureto is pretending to torture Shinoa while interrogating Guren, she sends Kureto a message telling him to do as he pleases. Her IP address tracked, Mahiru receives a message from Guren so calls him. Where the phone is put on speaker, Mahiru hears from Shinoa that everything went as she predicted. Twisting the conversation, Mahiru repeatedly states that all of the events occurring since the beginning are his doing. 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.

After Kureto releases Guren and Shinoa, Mahiru calls him again. Stating she only wants to hear his voice, Mahiru reveals the demon was in control before. They establish a rendezvous at 5:30 p.m. in apartment 501 located fifteen minutes from Ikejiri-Ohashi Station. The demon experiments going on in Mahiru and Shinoa are read by Guren. The research notes reveal the sister's origin and how the demon will drastically increase when Mahiru hits puberty. To prevent Shinoa from suffering the same fate, Mahiru joined the Thousand Nights and used herself as a test subject.

Mahiru does not arrive until 7 p.m. Although she tells Guren he cannot save her, when he insists he can, they have sex that evening. After asserting to Guren that he wants to protect his own comrades rather than her, Mahiru reveals she now has both her demon and Shinoa’s inside her body, which has sped up the rate of her degeneration. Having shared part of the demon with Guren in order to remove all of the demon from Shinoa, he will eventually become a demon as well. When he asks to fight by her side, Mahiru tells him there is not enough time and reveals the Apocalypse occurring that Christmas. The vampire who chased Guren and Shinya the previous night enters through the balcony and greets Mahiru, and in response she calls upon Asuramaru to quickly kill her. Mahiru reveals she fabricated information to set the Hīragi House and Thousand Nights against each other. After Guren says he refuses to let her give up her humanity, Mahiru jumps out the window. When Guren learns that the Thousand Nights is attacking the school and leaves shortly afterward, he comes across a running motorcycle and a demonic sword waiting for him in an alley that was presumably left behind for him by Mahiru.

She has an illusion over the whole school and is responsible for instigating the conflict between the Hīragi and the Thousand Nights. Showing up when Mito, Shinya, and Goshi play video games at Guren’s apartment, she is attacked by Guren, causing them to fall from the twenty-fifth floor. Mahiru stops her fall by using her sword.

Visiting Yūichirō Hyakuya, who is being experimented on and abused by the Hyakuya Sect, she asks him about his reason to live and if he has no right to live if he is a demon. If parents tell their child to die, Mahiru questions Yu whether that child would have no choice, then asks further what law says that. Since his mind has not broken from his experiences, she tells him he will find an answer one day. A researcher says he will erase all memory of this conversation from Yu’s mind, and Mahiru asks about receiving one of the Hyakuya orphans to experiment on with cursed gear. Called by Kureto, she is told in explicit detail about how he will torture Guren. Laughing in response, Mahiru says she is going to Kyoto. Visiting one of the Hyakuya Orphanages with the pseudonym, Miyuki Yamada, she chats with Akane Hyakuya and realizes she has a crush on Mikaela Hyakuya, one of the subjects with a body well-suited to experimentation. She “adopts” a child named Junji Haiyama before taking him to a van on the opposite side of the street. Killing the driver, and knocking Junji unconscious, she enters the freeway but is attacked by vampires. Fighting them, they cause a large car pile-up. Captured by the vampires, Mahiru is taken to Kyoto.

Tied to a cross deep within Sanguinem, she is being tortured. Mahiru is approached by Krul Tepes and asked if she is ready to talk. Revealing the date is already December 20, Mahiru summons Shikama Dōji and breaks free. When Krul asks Mahiru about Ashera Tepes, she only laughs.

On December 2, Mahiru leaves Sanguinem as a vampire sired by Krul. Although given a ring by Saitō to protect her from sunlight, she attacks him with Shikama Dōji. Knocking out out a human woman, Mahiru drinks her blood and notes that it tastes different depending on the age and sex of the human. Furthermore, the blood turns bad once the human dies. Mahiru then returns to Tokyo. By December 10, when Guren has been sent by Kureto to take care of students that have become possessed by demons at the school, where he has arrived first and knocked out one demon-possessed boy, Mahiru appears and applauds Guren’s strength. Admitting that this was her doing, Mahiru asks about the experimentation on Asuramaru. Explaining that a human must be modified in order to use a Black Demon, the current success rate is less than 20%. After Guren says he wants to protect both her and his friends and asks that she surrender, so he can extract the demon from her, Mahiru throws down Shikama Dōji and instructs him to give it to Shinoa in order to protect her. The rest of the group arrive and Mahiru is attacked by them. Drinking Guren's blood then expressing how delicious it was, Mahiru escapes. Called by Guren that he will betray the Hīragi and join her, Mahiru laughs in response.

On December 23, 2012, Mahiru has her call with Shinya shared over the audio system of the minivan they were in so that everyone could hear the sound. Apologizing to Guren and telling him she is too motivated by another invitation two days before Christmas, Mahiru speaks how it is too late. With it raised whether there is a third party involved, Mahiru answers him if he is concerned. Telling him that she loves him and romantically likes him, Mahiru is happy knowing that the call is being tapped. Continuing to laugh at hearing their conversation about betraying the Hīragis, and maintaining that she loves Guren, she tells them most of the clans are planning a revolt.

When asked by Guren where they could meet, Mahiru answers if she loves him now. After Guren asks again, Mahiru tells him she is busy and it is a secret since she will kill Kureto. When Guren questions how can they meet, Mahiru replies after killing Kureto she will contact him. Mentioning for Guren to try to survive, the call ends.

Discovering that Kureto is in First Shibuya High, upon being spotted by him, Mahiru is assailed by the lightning from Raimeiki. Dodging all his attacks, as Mahiru overpowers him easily, she laughs until Kureto regains his composure. While his sword is swung against her neck, in hitting his face to escape, the strike crushes his left eyeball and damages his brain as Mahiru gains the upper hand. In taunting Kureto, his eye has healed and Mahiru notices two hundred snipers aimed at her. Knowing it is just an illusion, in trying to escape, Mahiru's hair is grasped by Kureto. Damaged severely by a lighting bolt from Raimeiki, her internal organs are burnt and Mahiru wonders if she will die.

Hearing Kureto laugh that it is his job to kill her, with the two hundred snipers ordered to finish her, Mahiru manages to recover, break his neck and throw him. Aware that all the snipers are charged with cursed bullets, Mahiru reveals her first-class vampire weapon which is used to slice all the bullets effortlessly. Although seemingly at Kureto's mercy, Mahiru brushes it off as she used her own curses, then generates her own illusions to perform small tornadoes and a hundred monsters. When Kureto, in desperation to defeat her, orders his soldiers to kill her, since Mahiru is also a Hīragi they would commit a crime. While Mahiru overpowers him completely, Raimeiki can keep him alive. Knowing that killing her is an impossibility, Mahiru laughs.

Informing him about the Hīragi revolt, asked about her intent, namely if she is buying time, Mahiru tells him that he is too an important brother to be killed. Adding that she will take full responsibility for the Hīragi fall, Mahiru asks him why does the Hīragi have such power. Questioned in turn why does she even fight, Mahiru's response is the world will end and it is definitive. Not responding when he tells her who made such decision, before leaving Mahiru told him to treasure Guren.

Phoning Guren at 22:35 and requesting he become a psychic so he can see the future and prevent his friend deaths, Mahiru tells him to do so even if the world would end. Hearing Guren say he betrayed everyone just to be on her side, on whether she should reward him and has he had a painful life, Mahiru does not reveal her location yet claims he cannot protect her. Asked why would she call, Mahiru then laughs again when Guren thought that he wanted to protect her and hear her voice. Detailing that this is just his hypothesis and he actually wants to see her, when Guren was protecting his friends, Mahiru wonders if he is protecting another woman.

Deciding to reveal her whereabouts, Mahiru shares it is the laboratory in Ginza that the Hyakuya Sect once owned. Baiting Guren and lying to him before ending the call, she wanted to hear Guren's voice and him say he will come to Ginza. Thanking Guren and speaking she loves him, Mahiru states she is waiting for him. When Guren ends the call, Mahiru had a sad expression.

On December 25, Mahiru's location is revealed by Kureto to Guren to be in an underground laboratory that spreads to Shinjuku Central Park. It was the research institute of the Thousand Nights. With her involved in a ritual that would cause destruction to the world, Mahiru is wondered about as Guren and the group contemplate whether she can be stopped or saved. She is in their minds further as they form a formation to defeat her. Drinking the blood of humans, Mahiru had killed many and left nearly twenty corpses. As much as she is happy to see Guren again, Mahiru is firm that it is impossible to save her.

Unable to be scratched, Mahiru immobilizes the group's formation, leaving them struggling. Gleefully overpowering them, Mahiru hears Guren state that he came here at Kureto's request. Ignoring this news, Mahiru advises him to worry about his friends recovery instead. When Guren affirms if he hadn't had friends he would never be able to reach here, Mahiru tells him to kill her since that is the only way to save her. After Guren refuses to do so, Mahiru asks him the meaning of life then.

With Guren's friends having recuperated and established another formation, Mahiru hears Shinya mockingly tell the truth about her obsessed affection for Guren. Told to accept her own weakness since it is still not too late, while Mahiru listens, she is angered. Silencing Shinya, and stabbing him to pierce his chest, Mahiru tortures him more by keeping her arm jabbed deeper into his body despite Guren's attempt to save him by begging her to stop. Asking Guren again the meaning of life, Mahiru's question is unanswered where Guren was losing his sanity by Noya's consumption and his devastation at Shinya's death.

Asking Guren if he hates her now, while he agrees calmly, Mahiru hears him deny he is going to kill her. Wondering why since she done horrible things to him, even killing all his friends, Mahiru listens as Guren tells her if would ever let his anger out then his friend Shinya would be angry. Telling him that Shinya is dead, when Guren responds even if he is dead they can win as his destiny will lead him, Mahiru states that Guren is weak and death is simple for him. As Guren throws away Noya knowing full well he cannot win using it against her since Mahiru abandons her weakness and always seeks the strong way out which, it is said to be something she repeated multiple times. Mahiru tells Guren she did not throw away her weakness as she views him to be strong. Although Mahiru asks him to save her, Guren has had enough of this since everyone is dead, where even if that it is his wish it has been granted.

Taking her phone and seeing it is only few hours left until the end of the world, Mahiru speaks to Guren about the forbidden magical experiment the Seraph of the End. On what will happen if it is activated, from all the information Saitō told her, Mahiru explains the Seraph of the End as the controller of God's punishment. While Guren denies the existence of God, she mentions to him if there were a god there must be a reason to create a terrible world. Having the view that heavenly punishment is such an amazing power, Mahiru also feels that manipulating it any further would be bad.

After picking up Noya and welcoming it back, Mahiru hears Guren raise the idea to save her for a final time. Crying while answering that it is impossible, Mahiru stabs herself using the Noya blade in her heart. While a confused and panicking Guren tries pulling the sword out of her, Mahiru warns him that she integrated with Noya into her heart. Laughing as she weakens, Mahiru is embraced by Guren as she starts suffering from the curse. When Guren wants to know her desire, Mahiru simply wanted to be an ordinary girl.

The curse spreads over most of Mahiru's body, and where Guren is worried about her death, she tells him it was her plan to die. Sharing details about her experimentation, Mahiru adds due to her birth the heavenly punishment was solely for her. Since her mother was mixed with a demon, Shinoa and herself made countless sacrifices and Mahiru ends that this was planned. Eventually, Mahiru's body is dyed by Noya and the curse. Mahiru's dying words are that she touched the taboo he controls, and she still cries happily at Guren having coming here with his friends to confront her.

"They can take my body, but they can't take my soul. That's why when I'm reborn, I can just be a normal girl."

- Mahiru's last words.

After Noya's curse has spread over her body, whom he was absorbed by Mahiru. Mahiru and Noya become the being Mahiru-no-Yo. After the sword fell on the ground.

Post-Shinjuku Arc
When Shinoa goes to meet Guren at the lab underground, Mahiru is mentioned as having invented Cursed Gear, and that sacrifices are necessary. While this is discussed, Mahiru is visualized. Her name is spoken by Guren during a fight with Yu when he invokes his demon, which is heard by Shinoa. When Guren calmly says he would let Shinoa kill him, she asks him if that is his way to atone for killing her sister, Mahiru. Questioned whether Mahiru is in his sword since her name was called, it is mentioned that she is already gone. Having turned into a demon, it saved the world by completing Cursed Gear. Stated by Shinoa that Mahiru was never one to care about the world because she loved Guren, it is said she longed to be with him since they could never be together, and because Mahiru became obsessed with demons.

After discussing the events of eight years ago, Shinoa says that if Mahiru had not completed the development of Cursed Gear, humanity would have perished. Said to be Shinoa's half-sister, Mahiru is referred to as just a girl in love who became something like a Messiah, but then she was killed when she became obsessed with her research. Becoming a demon due to that, she is discussed as Shinoa details that the one who killed Mahiru was the person who used to be her lover, Guren. Where Shinoa asks Guren if Mahiru is together with him inside his sword, the other concern it that he is being possessed by her. As they speak, it is mentioned Mahiru was not close with family as Hīragis are raised without knowing familial love.

Her possible directives come to light when Shinoa asks if making use of Yu was one of Mahiru's orders. In asking if her half-sister or the demon for lack of a better word inside his sword is ordering him, Mahiru's past desires are not taken into account by Shinoa, who asks Guren to stop what he is doing if his goal does not benefit Yu. Affirmed by Guren that Mahiru is dead and is not coming back, according to him the demon inside his sword is under control so he isn't being possessed by her, a claim not believed by Shinoa.

Osaka Arc
After the fight with fifth progenitor Ky Luc, Asuramaru wanted to know what trauma has led Yu to be who he is. Mahiru is seen by the demon in a flashback. In it, she talked with a traumatized eight-year-old Yu, who was being held by the Brotherhood of a Thousand Nights.

Shibuya Arc
Mahiru is mentioned by Kureto as the reason why Shikama Dōji targeted Shinoa, as she is her younger sister. According to Guren, he shares that it was in fact Mahiru who found Yu and that before she died she made connections with a second progenitor involved with the Hyakuya Sect: Saito. Whether Mahiru chose Saitō to take action against the first progenitor that was going for her is contemplated by Kureto in his discussion with Guren and Shinya.

When Mahiru-no-Yo is struck by Guren's sword during the assault on Shibuya by the Hyakuya Sect, the joint being of Mahiru-no-Yo is separated back into the component beings of Noya, and Mahiru herself. She appears in pain as Noya breaks out before laying motionless. In a spirit like state, Mahiru bears the chest wound as she floats before Guren and tells him to not say much in his demon state. With Noya offering the opposite advice, Mahiru swings the sword to Noya's mouth and orders him to be silent. Mahiru faintly smiles in silence at being recognized by Shinya. She joins Noya, and Guren as a demon who is supplementing his power with chains (together being referred to as Mahiru-No-Yoru) in combining their energies above them.

Invisible, the spirit of Mahiru joins Guren in arriving at where Shikama Dōji battles with Saitō. She is able to halt the scythes sent by the First towards herself, Noya and Guren. Where the First is possessing and in control of her sister's body, Mahiru tells Shinoa to hang in there as she will rescue her. Voicing her surprise at Saitō betraying them when he intends to use his fangs to bite Guren to acquire the Sinful Key and gain their powers, with the assistance of Ferid using Jigenso to deal with Saito, she along with Noya and Guren all acquire a sinful key each. Part of the three forces surrounding Shikama Dōji in Shinoa's body, Mahiru holds her sinful key to emit a sinister power the entrap the First. There to catch Shinoa in her arms after Shikama Dōji leaves her body, Mahiru says her name. Managing to wake her, Mahiru is recognized, then stays alert.

Later she finds Mika debating his next move concerning Guren, and appearing behind him, she answers his question that saving Yu is way beyond him, then returns his sword strike with one of her own. Complementing his speed, she is aware that he is Krul's vampire and when asked who she is, Mahiru joyfully introduces herself to Mika by stating she is everybody's favorite lovely idol. Mahiru remembers her task, and reveals her plan has a time limit.

"Oh right, right. Now isn't the time. I have to hurry and overwhelm you while the life-absorption barrier is still up..."

- Remembering her time limited plans before engaging Mika in combat.

Charging at him whilst asking if that is okay, her sword attacks are avoided by Mika and she expresses worry at Mika's weapon coming close to her. Making use of shikigami-talismans, Mahiru appears behind Mika cheerfully stating she has got him, he loses and goodbye. With her sword avoided, she notes he did not lose and remarks that Mika really is fast. Mahiru does feel he lacks skill and detonates several spell tags, telling each one to explode and they do so across the top of buildings, laughing as she does this. With Mika forgetting her to save Yu, Mahiru supports this decision, stating aloud for Mika to run off and save Yu. Mahiru appears in the sky in front of both Yu and Mika, and greets Yu happily mentioning it has been forever. With Yu not knowing her, she asks if he does not remember her from the prison when Yu was five and called demon spawn. Reminding him that his own parents tried to kill him, a lone monster all lost and alone with no reason to live, Mahiru asks him if he has found a new reason. Triggering some of Yu's memories, a flashback is shown back when she visited Yu as a child in a prison then heard that he was demon spawn and a monster where everyone would be happy without him in the world. Mahiru questioned whether monsters are allowed to live too, and even if parents tell their child to die, does that child have no choice. Mahiru queried what law says that before being informed by researchers that it is useless talking to that test subject as they will manipulate his memories either way. In the present time as Yu remembers they met, Mahiru magically produces a glimmering stream of spell tags from her hand. She smiles in silence at hearing Yu answer her question, that he had found a new reason to live in Mika. With Yu and Mika evading them, Mahiru tells Guren she has planted wards all over, questioning if he wants her to cut off their escape route. Instructed to get back inside him, Mahiru blushes after interpreting the message carnally before remarking that Guren is so lewd. Encouraged by Noya's comment, Mahiru asks whether she and Guren get to make out in public. As Mahiru shows a happy face and blushes even more, she obliges with his order to return to the sword. As Guren faces Yu and Mika, Mahiru alerts Guren that they are coming. She is called upon to auto-block the invisible swords that Yu has in store for them.

Post-Shibuya Arc
Later Mahiru is floating behind Guren with Noya, and covering her ear she comments to Guren that it is finally beginning. She laughs at Noya's question on what Guren injected into Mika's hand during their fight. Telling the little demon to not worry, Mahiru is able to hold a needle and inject a substance into Guren. Two large horns appear out her head as she says for her desires to be eaten and grow even stronger. Considering it strange, she can sense fear and comments that if demons get scared they will wind up getting eaten by humans just like them. Replying to Noya on what she and Guren are after, Mahiru asks is it not obvious, before clarifying that it is love.

"What are we after? Isn't it obvious? Humans only ever want one thing... Love."

- Her answer for Noya regarding what she and Guren are after.

Complying with Guren's order to shut up and finish it, Mahiru stabs a needle into Noya. She then questions Guren on Mika's status and hears that vampire Mikaela has died and now he is transforming into a black demon. Mahiru watches the event unfold.

She is mentioned by Krul and was aware that their deal involved a demon transformation. Mahiru is visualized when Krul mentions to Shinoa squad that the current plan began with her. Mahiru is mentioned by Krul when she questions Shinoa's relation to her. Described by Mitsuba as the genius who invented the Cursed Gear and died, Mahiru is visualized when it is discussed that without the Cursed Gear humanity might have gone extinct after the catastrophe. Most people consider Mahiru the savior of the world yet there are rumors that Mahiru betrayed the Hīragi family. Mahiru is mentioned by Yoichi who queries if she is the one who was possessing Lt. Colonel and also by Kimizuki who thought she was manipulating Guren.

Recalled when Shinoa's past is raised they were both the only two guinea pigs who survived experiments to birth exceptional children. This was done by having a gifted follower of the family artificially inseminated with seed imbued with a curse. There were high expectations for Mahiru since she was a genius and it was believed by Shinoa that Mahiru was being experimenting on more. In one case Mahiru came across Shinoa and asked her how was it. Hearing that Shinoa was incompetent Mahiru replied that was too bad, when she herself is such a genius too. Cheerfully greeting the scientists present Mahiru announced that their lovely genius heroine has arrived and for them all to conduct some happy little experiments today.

Later during this past event Mahiru watched a match between Seishirō and Shinya within an amphitheatre. Mahiru then takes part in sparring against Kureto and answered that of course she will not hold back. After avoiding his sword Mahiru effortlessly beats Kureto by throwing him over her shoulder and placing a spell tag on his forehead. Sat on on top of him Mahiru joyfully announces that was close and that her bother is so good. She faces Shinoa who is observing nearby.

A photo of Mahiru with Guren was seen in the young Shinoa's room. Mahiru joins her and upon holding the frame she gets excited and asks Shinoa if she will ask who is the person in the photo. Even though Shinoa did not ask, Mahiru continued anyway, informing her sister that his name is Guren, and he is so cute and so nice. She continues that he tries hard at everything and even though they are of totally complete different status he cares for her. Sharing how she is in love by just thinking about Guren where he makes her heart feel warm and skip a beat, Mahiru then asked 'Shi-shi' if she has ever been in love. After Shinoa denied it as she is only four years old Mahiru in return said she fell in love when she was five yet acknowledges that Shinoa probably has not. When Shinoa mentions she is not even sure what love is, Mahiru replied she will someday as they are both girls.

Mahiru changed the subject to how they were born with a demon already implanted inside of them. Love, despair and emotions such as them all boil down to desire. When their desires go wild their demon will try to control them. Wondering if Shinoa has had dreams Mahiru advised Shinoa that she cannot ever let anyone know she has them. They are both already guinea pigs, and if they find out they have demons inside they will subject them to experiments that would kill them. After warning her, Mahiru asked whether they had taught Shinoa about periods, namely menstruation and menarche. Explaining that it is something that happens to girls when Shinoa's comes her desires will really start to run rampant where keeping the demon under control will become even more difficult. Before that happens, before they come, and anyone finds out Shinoa has that power Mahiru stated that she is going to completely destroy any emotion Shinoa might have. Shinoa is physically assaulted by Mahiru, with the goal of destroying her emotions. Every day starting then Mahiru will beat Shinoa bloody and traumatize her so badly that she will not remember anything. Following the words up with action Mahiru began punching and kicking Shinoa with enough force to knock her over. Mahiru spoke for Shinoa to let the pain engrave this deep in her mind. No matter what torture they put her through she will not react and Mahiru questioned whether she was understood. Telling Shinoa that her existence had no value, that she was incompetent, Mahiru added that Shinoa was helpless and had no will or emotions.

Noting that she has beaten Shinoa this badly but she can still react as she did Mahiru said breaking her is going to take more effort than she thought. Disregarding Shinoa's concerns that she would be left alone Mahiru answered that she would be fine and was a genius after all. In response to Shinoa saying she wanted to help Mahiru struck her and labelled her dead weight. Checking some blood Mahiru told Shinoa it was okay and that she was in complete control of herself. She had been experimenting on herself in secret to make certain that she keeps control. Someday she is going to cut the demon out of Shinoa and take it into herself then Shinoa can go back to being a normal human. Answering that she cannot be a normal girl anymore Mahiru feels she could not give this defiled body of hers to Guren, not after it has been experimented on so much and for so long. After a thought Mahiru states it will not happen, it is a dream right out of a shoji magazine. The world is not that kind and Mahiru continues that if let herself fall in love then she would not be able to protect her baby sister. Hitting Shinoa away Mahiru says for her not to worry she will take care of her emotions, memories and any desires that her demon could use. Meaning to make it all go away so that no one ever notices Mahiru will break Shinoa into bits to keep her safe. Acquiring a box Mahiru tells Shinoa that she loves her where a hypodermic needle is shown as Mahiru tells her goodbye.

Mahiru is then remembered in Krul's flashback, that she came to visit her. Facing Krul on her throne, Mahiru greeted Krul as her majesty and stated that she is just a human. Mahiru shared that she knows the location of Yu, Mikaela, as well as Ashera Tepes and has come to tell her.

Mahiru is floating besides Guren running across the town. As they hurry Guren complains, and Mahiru asks what's with the complaining, as he's not the type to complain, but Guren tells her that he's the type to complain and he does it to Shinya and the others which ticked Mahiru so much. Mahiru hugs Guren telling Guren that she is the only one he should complain to, as she will listen to all his worries and solve all his problems in all his life. She then asks Guren what was bothering him, he tells her he let his demon go berserk and now he is sore. Mahiru is healing his shredded muscle fibres so they do not turn necrotic but it will take at least ten hours to heal completely. She also says there is no time to rest, asking how much longer the curse-amplifying drug they injected into Mika is going to last. Since once it wears off Shikama Dōji will be able to locate and capture Mika right away, and before that happens they need to find Mika and turn him into a Cursed Gear. Mahiru then takes out a needle and inject herself Mahiru says it is something that suppresses the cells of the first that were both injected into herself and Shinoa. Guren tells her she's not weightless anymore as she hold into him.

When Krul thinks back to eight years ago in the vampires' third capital of Sanguinem, Mahiru spoke about herself, how was her life stolen away from her upside down, born into a cult created by the first and her own body had been implanted with the first's own cells. She materialize her scythe around her, giving a show of how despite her self-proclaimed charms she was not even permitted to fall in love. She had her entire life calculated and planned out, and was seen as ultimately a dance choreographed by Shikama Dōji. Mahiru shared that it was already decided that the year then on Christmas day that she was going to die as a sacrifice at the moment the upcoming calamity destroys the world. Voicing it to Krul how unfair it is. Krul doesn't care about her story life and only want to know the whereabouts of her brother Ashera. Mahiru answers that just as she has been, Ashera is also being used by Sika Madu to this very day. Angered, Krul seizes Mahiru, ordering her to tell her where Ashera is. Mahiru asks Krul for patience, taking out a needle to suppress the first since she would like their pact to remain secret so they can carry it out without Shikama Dōji overhearing. However Mahiru falls to the ground and spits blood from the injection, she says that her internal organs are rupturing and can't heal since the drug was too potent. Not wanting to die, as there are people to protect until Christmas. Mahiru spoke as they need to work together and their interests ought to be in line. She requests Krul to be turned into a vampire to prevent her from dying. Krul asks her what is she after, and Mahiru desires her life to be in her control not the first's, neither the cult's and not event fate's. Mahiru would be the one to pull the strings in her own life.

In the present, Guren along with Mahiru crashes through the window. Mahiru shouts out it's a good thing that the drug is still working. As Guren announces that they are going to turn Mika into a Cursed Gear. When Yoichi and Kimizuki are angry at Guren for killing both their sisters, Krul proceeds to silence them but Mahiru places a finger on Krul's mouth and tells her not to worry, this will all work out. Krul asks whether Mahiru will silence them. She won't but her sister will, as her sister is truly gifted. When Guren blames himself for the catastrophe, as he Shinya and the others were supposed to die with him. Mahiru consoles Guren that it isn't his fault, and Shikama Dōji arranged for it to happen. With Guren's plan to resurrect all of humanity, Shinoa queries whether that is what Mahiru has been doing, Mahiru replies that that she did fall in love with a big dummy. Mahiru then asks what is the unexpected problem that concerns Shinoa, and she reveals that Asuramaru is an enemy as he was ordered by Shikama Dōji to capture Mika's soul.

When Guren, Kimizuki and Mitsuba were drawing a spell circle, Mahiru feels it's about time, and casts some spell tags. She then pulls Mika's sword from her chest, and is stabbed on the ground. Later Mahiru and Guren are surprised that Yu can hear Mika is in trouble. With demons losing their memories when they are born Mahiru suspects it could be one of Shikama Dōji's traps. When asked by Guren how does she have her memories Mahiru answers she used a special spell to turn herself into a demon instead of being created the normal way. Asked if they should stop the plan Mahiru is against this since it could be a trap designed to get them to do just that. Asked about her thoughts on the matter considering Shikama Dōji's possible awakening Mahiru replies she has no idea. If this is messed up, Mahiru feels their plan twenty four years in the making may be all for naught.

"Mess this up and I guess we'll be stuck cursing fate and wondering what we spent the last 24 years doing."

- Speaking with Guren when deciding whether to proceed with their plan.

With that alternative Mahiru guesses she will let her Prince Charming make the decision. Floating near Guren on the now activated spell circle Mahiru sets aside why Guren is standing on Yu before judging Guren's rally to take care of family to be a good decision. She is near as Guren speaks with Yu on whether one of them would want to go on if the other died.

Hearing that Kimizuki and Yoichi's demons are collaborating with Asuramaru, she sees how it is. Thinking it was her idea to have nothing but black demons here, Mahiru now feels even that was part of the first's plan all along. Mahiru hears confirmation from Shinoa that she still has a hold on Shikama Dōji, although he is starting to wake up. Hearing Shinoa say she will force him back to slumber, Mahiru tells her it is good then. Reacting to Shinoa losing control of Shikama Dōji and that he is going to wake up, Mahiru tells Guren she is taking another dosage of the drug. Warned the last one was too recent, Mahiru feels if they mess up here it is all over. Calling to Shinoa and saying she will help suppress him, Mahiru asks her to hang in there a bit longer. As she injects herself in the neck, Mahiru resolves to crush every one of the First's cells in her. After collapsing, Mahiru checks with Shinoa what the situation is.

She is visualized along with Shinoa when Shikama Dōji details how in all these millennia, these two are the first to ever surpass the parameters of his plans. It is recollected how Mahiru was beside Guren as he told Yu that failure was unacceptable and had to beat Mika by striking him.

As Mahiru is held by Guren where a chain has appeared out of Kimizuki, she reacts to Saito's voice coming out of it. Announced that the time has come for them to put their plan into motion, Mahiru listens as Saito explains the drug given to them can be used so Kimizuki's power can reach Yu and Mika to be saved from the First's assault. Reacting to Guren's call, Mahiru casts injections to Yoichi and Kimizuki. Ordering to do it, Mahiru provides the means for them to control their demon.

"Do it! It'll give you control over your demon's hearts!"

- Shouting commands to Yoichi and Kimizuki to inject themselves as Mahiru resumes Saito's plan.

Called by Shinoa to give the drug she is using, Mahiru details it is poison. Adding that it is lethal, Mahiru questions whether Shinoa is sure. With it observed she is using it, Mahiru lightheartedly replies she is already dead. Complying with Shinoa's request, Mahiru passes her a needle.

Mahiru is envisioned when Mika is considering how Guren had an ulterior motive in rescuing Yu. Behind Guren and speaking what she apparently feels, Mahiru continues it feels like they have driven off Shikama Doji.

"Guren. I think it worked. It feels like we drove off the First."

- Having some notion of events, where Sika Madu was indeed taken away by chains.

When Guren comments if that means Yu will come back, Mahiru teases whether he is that happy. She then notices that Yu has returned. Calling Guren that they should get out of here, Mahiru is wary that the First will find them. Told there will not be any problems as everything is working so far, Mahiru responds they are only humans, yet they only get one chance to pull one over on the gods.

When Mika is accessing Yu's memories, Mahiru has herself entered the memory of Ferid murdering the Hyakuya orphans. Where she stays in the shadows of the Sanguinem exit hallway, Mahiru Seemingly stares at right at Mika. Active in the physical world, Mahiru moves and approaches Mika from behind. Questioning him whether he saw her in the past, Mahiru then asks if he can see memories from before this Yu was born. Asked who she is, Mahiru answers that she is simply a women in love. Calling to Yu and Mika, she feels the real question is who really are they and coming close to both of them, she wonders how many tens of years have they lived. From now on they are going to figure it out.

Akihabara Arc
Now in a truck driven by Ferid, she sits beside Guren with Krul nearby, and grins at Mika opposite her. Mahiru is envisioned when Mika is explaining to Yu that she, along with Guren, Ferid, and Krul are involved together in some kind of grand plan. When Yu flatly asks Guren what this grand plan is, Mahiru laughs at Yu's comment before remarking that he is a funny boy. She listens as Yu speaks to Guren.

When Yu was about to smash the truck, Mahiru is called upon for power. Acting to grant it, she becomes his sword to block the attack. Invoked by Guren, she generates the "Moon Demon Stance", to create shadows around them before the weapon form clashes with Yu and Mika. Thrown apart, the sword is stabbed in the side of a building for Guren to keep himself there. Mahiru teases Guren if he is moved by him after he complements Yu's strength. Questioned what she thinks, Mahiru informs him that she adjusted the amount of poison to throw them off. Notifying Guren with two more clashes he will be faster, after Guren mentions that he as well adjusted the amount of his speed, Mahiru updates it to once then, one more clash and they will have won. When Guren later lands on the ground, and activates the "Mahiru. Moonight Stance", ovals increasing in size outwards around him are generated. The sword radiates shadows as it nears Yu and Mika.

The sword strikes the one Mika is within and continues to administer poison. It remains in the grip of Guren. Called for power, the weapon handle emits shadows, before streaks of light shoot outwards. Inactive, it remains in Guren's hand. Standing alone in a landscape, Mahiru whether Guren is going to dodge. Where he is silent, Mahiru questions further if Guren is going to let Yu win. If Guren wants to bother trying, Mahiru details they have a dozen spells they can use.

"Aren't you going to dodge? You're going to let him win? If you want to bother trying... ...We have a dozen spells we can use to win."

- Speaking to Guren concerning the fight against Yu, and sure they can win.

With Yu said to be throwing his honest feelings at them, the question is if there is a point to winning if it means getting tricky. Honestly speaking, Mahiru does not really see the point of losing after coming this far. She follows up a question whether Guren really wants to lean on him. Additionally, Mahiru asks if Guren wants to give in and acknowledge Yu's feelings for him.

After Guren remarks that he is so weak, at first Mahiru rejects that idea, replying that he is not. Then considering this statement, Mahiru re-evaluates her point of view and affirms that he is weak, but that weakness is that she and Shinya admire. Commenting that Guren is an idiot who is not afraid to admit his weakness while still trying so hard to save the world, Mahiru takes ahold of Guren's arm as she says to do whatever he thinks is best. The sword Mahiru is in lies nearby to Guren on the ground.

Mahiru observes while listening to Shinoa's words, whom she shouts her concern about the Hiragi family and reviving the dead. When Shinoa mentions that Mahiru had her life worse, comparing how Shinoa kept her heart close, so Shikama Doji wouldn't possess her. As she states that Mahiru sacrificed her whole life to protect her. Mahiru reacts to her words. She remains silent when she regards Guren response. Guren speaks how Mahiru said she did not want him to be collateral damage in her curse. Where Mahiru wished Guren had not come to rescue her. Mahiru listens on Shinoa words about how she and Mahiru were caught up in those plans since birth, with absolutely nothing they could do but despair, until Guren came along to try and rescue them. Both Guren and Mahiru sheltered her from them, going away to suffer all by themselves. Later when Yu joins hand for a circle Mahiru chuckles when Yu calls out for Krul. Mahiru then joins hands in the circle.

When the group reaches to their destination at an underground facility, Mahiru is present nearby Guren and her sister Shinoa. When Yu tries to escape outside, Guren calls out Mahiru and she turns into a sword. Guren invokes Mahiru-no-Yo, using her to attack Yu.

Natural abilities
As a human, Mahiru was an exceptional fighter, being the most prominent candidate to be the next leader of the Hīragi Clan, stated by Shinoa to excel in all fields of combat as the best in be it magic, swordsmanship and hand-to-hand combat. Mahiru has been shown to be vastly superior to all her siblings, even Kureto, which he openly admits, Mahiru effortlessly defeating him in one of Shinoa's flashbacks that had them sparring, even going as far as to easily dodge Kureto's sword attacks without having to block and casually catch his shoulder before lifting and throwing him to the ground with one hand, going as far as to casually mock her brother for his poor show and Kureto even frustratedly acknowledging Mahiru was simply toying with him, and Shinoa herself despite her own excellent skills noted that Mahiru far exceeded her abilities, with Mahiru effortlessly beating Shinoa to a bloody pulp. Likewise, Guren noted her skill exceeded even Shinya, one of the best fighters in the school, with Mahiru easily defeating him in their first meeting. She was so much stronger than Seishirō that after easily parrying his attack on Sayuri with one hand while the other held the girl, she easily intimidated him to submission despite his arrogance. The most skilled of her class in fighting skills, her movements were acknowledged by even Guren to be quick and graceful. She is also able to easily fight on par with and pressure Guren in a sword fight, though Guren noted he was better in swordplay than her, albeit it must also be noted that Mahiru may not be fighting fully either, as she wasn't trying to kill Guren and was merely wanting to show the power of her Cursed Gear, proceeding to easily intercept his attack on Saitō and nonchalantly destroying his sword.

Noted by Kureto and Shinoa, Mahiru was also intelligent and a genius. She's one of the early pioneers of the Cursed Gear, which is essential for mankind's survival ever since the Apocalypse. At a young age, Mahiru is able to extract the growing demon inside Shinoa, but at cost of her own humanity. She is credited for completing the Cursed Gear and hailed as a hero. In Catastrophe, upon losing her humanity right after transforming into a vampire, Mahiru noted to herself that she has finally managed to obtain strength, which is equal to a third progenitor-like Krul Tepes. Whereas a vampire's power is dependent upon both age and lineage, it's unknown if Mahiru was really as powerful as she believed to be. This is because Mahiru was still a young teenager, in comparison to Krul, who has lived for a really long time, though she expressed strength far surpassing Guren and Kureto even with Kureto's power augmented by Raimeiki. Guren admitted himself he is no longer a match for Mahiru.

Unlike Mikaela, who also became a true noble vampire by Krul, Mahiru doesn't seem to have a first-class vampire weapon in possession, but still used the demon weapon, Shikama Dōji with its forms and abilities instead. Though it is later revealed that she possesses her own a first-class vampire weapon as shown when she fought Kureto. Upon discarding it, Mahiru can truly unleash her potential power as a true noble vampire, which is greater than that of a demon she originally became before the events of Seraph of the End occurred. Even so, despite the tremendous power she has greatly attained from Krul, it was still not far from enough to even scratch the second progenitor Saitō and defeat him. However, she was still effortlessly capable of dispatching the entire Guren Squad, as Mahiru was able to pierce a hole through Shinya's chest and lift him nonchalantly with the hand impaling him, killing him before even the squad noticed her, and killed the rest of Guren friends easily.

Equipment

 * Vampire Sword: Upon Mahiru's change, she also came into possession of a weapon that could improve its own, and her own power by draining her blood.

"Drink in blood, blade of mine."

- When she takes out her vampire weapon.


 * Talismans: Although not often making use of talismans, Mahiru has also proven to be considerably skilled in using them and could skillfully use illusions with them. Her skills are so great that in addition to being able to easily trap Shinya, a notorious master of using magic in his own right, when they were young, in an illusion and then place and activate an exploding spell-tag, along with also trapping Guren in an illusion rather easily, she could simultaneously use more than 100 curses, a feat that astonished Kureto, as he can only use up to 7 while Mahiru can use more than 100 curses,Catastrophe Book 3 - Mahiru wielding Asuramaru.png using them to perform small tornado's and a hundred monsters in a battlefield in the same matter as Norito Goshi to easily counter Kureto's illusions completely.

Having a shikigami-shaped talisman, this kind allows Mahiru to dodge an attack if slashed. This is displayed when she kept using them to overwhelm Mika, noted to be a powerful vampire. Her skills are so great that Mahiru can even place multiple ones for surprise attacks for her to switch her location between the talisman, if slashed the shikigami would be cut in half and she would be in different location, this technique is both defensive and offensive, it also prevents opponents from counterattacking.

Cursed Gear
Having a hand in its creation, Mahiru also helped develop the demon powered weapons that would allow humanity to survive against far stronger threats. Cursed gear weapons greatly enhance the physical capabilities of humans, their potential to recover from injuries, and inflict cursed strikes upon foes.

"You look surprised. Amazing, isn’t it? A cursed weapon. It’s a combination of Hīragi and Thousand Nights magic. We learned how to make contracts with high-ranking demons that were formerly out of reach, and to bind them into weaponry…"

- Speaking to Guren about the Cursed Gear.

Where weapons range in power, Mahiru has wielded some particularly strong ones.


 * Asuramaru (阿修羅丸): Asuramaru is a possession-type demon weapon of the Black Demon Series. It resides inside a black sword that Mahiru once used. Whilst in use, the blade developed a thick green aura. She could call upon Asuramaru to fully use its power to attack opponents.


 * Shikama Dōji (四鎌童子): A manifestation-type demon weapon from an unknown series. It is strongest at mid-range. His primary ability is to detect anything that comes within the attack radius of his scythe.

Able to become a cursed gear herself, Mahiru can be invoked to generate powers for her wielder. She is also capable of creating effects on her own initiative and also able to estimate their power. For unknown reasons Guren can still invoke Mahiru-no-Yo despite Noya isn't inside her anymore. Even though before Guren was able to invoke only her name.

"I adjusted the amount of poison to throw them off. If we clash two more times, you'll be faster."

- Having inflicted poison onto Mika as a sword, and informing Guren.


 * Mahiru! Moon Demon Stance! Shadows of different shades appear largely around the hilt of the blade, before a more fiery energy is emitted outwards from the wielder. This can effectively withstand other invocations.
 * Mahiru. Moonlight Stance. With the sword pointed downwards to the ground, very large ovals appear around and expand outwards at various lengths. An after effect may be shadows winding around the blade.

Seraph of the End: Guren Ichinose: Catastrophe at Sixteen
Quotes from the Seraph of the End: Guren Ichinose: Catastrophe at Sixteen prequel light novels.

Catastrophe at Sixteen, Book 1
From Catastrophe, Book 1 "I’ve changed too, Guren. I decide who I see now, and what I do. It’s a Hiragi’s duty to look after the clans under our command."

- Mahiru to Guren.

"You were more rough-and-tumble as a child. When did you learn to say such flattering things? I don’t care if it’s flattery. I’m just happy to hear you call me beautiful."

- Mahiru to Guren.

"…do whatever I want? I don’t have any interest in making father happy and I never have."

- Mahiru to Seishirō when she saves Sayuri.

"I don’t want you to apologize to me. Especially not this weak you, who can’t protect the girls in his life."

- Mahiru to Guren after saving Sayuri from Seishirō.

"It’s not quite perfected…but I think we’re close. Just think of it, Guren. With a weapon like this, what is there left to fear? The Hīragis are powerless ants in comparison. Even vampires would be no threat. They think of humans as no more than mere cattle, but with a weapon like this we could kill them. It just needs to be perfected. Look at it. It’s so beautiful—"

- Mahiru to Guren.

"Since when did you become so high-minded? You act as if you’ve never sacrificed anything. But I have a feeling you’ve given up more than your share to gain the strength you have now. It’s a lesson we learned together, Guren. That day, on the grass, when the sky was so blue. Without strength, you can’t protect anyone. Not the ones you love, and not the things that are most precious. All that matters is power. I know that, now. And so do you, Guren… Come with me. I can give you power, Guren. We can perfect this strength together. We…we can—S-Stay away, Guren! It’s too late. Too late… The demon, it’s already possessed me. The cursed gear…our experiment… W-We failed… This isn’t me. I…I… Shut up! Shut up! No one is possessed! I just need power…more power…"

- Mahiru to Guren as she starts to struggle against the demon.

"I love you, Guren. That much is true. A day will come when you need me again… Until then, I’ll be waiting."

- Mahiru to Guren before leaving after their clash during the attack on First Shibuya High School.

Catastrophe at Sixteen, Book 2
Quotes from Catastrophe, Book 2 "My loyalties lie in the same place as yours do, Guren. Wherever there is power. Enough power that no one can ever interfere again. Enough power so that no one can keep us from the people we love, so that no one can take our freedoms away from us again."

- Mahiru to Guren.

"Everyone’s path is the same. In the end, we all die. Humans are weak. 'What is the point of living?' 'Are we here for a reason?' Time passes before we know it. Too fast for us to waste it asking such foolish questions. So, how do we live during that brief span? What path do we choose? We’re going to die either way. Do you really think taking the long way there changes anything? Ha."

- Mahiru to Guren.

"You’ve got it wrong. I’m not trying to pull your strings, Guren. The decision is yours to make. But you won’t resist it. You thirst for power. You need it. You’re just like me. You’ve already fallen. You’ve fallen deep, and there’s no climbing back out."

- Mahiru to Guren.

"Ahaha! In the end, it looks like you really don’t have a choice. That creature is a chimera. It’s been altered using the genetic material of the Four Horsemen of the Apocalypse. If you don’t draw the black sword from the ground, you’ll never be able to defeat it. You’ll die. And all your little friends, lying unconscious on the ground here, will die along with you."

- Mahiru to Guren.

"That’s it. Take the power that’s offered to you. Give up your humani… S-Stop, Guren, don’t! If you do it, you’ll never be able to return… Shut up! SHUT UP! He almost did it. You… I… Shut up!"

- Mahiru to Guren as she starts to fight with the demon.

"Ha! Amazing, just as I expected! Ah…hahaha… I bet you want to kill me too. You can’t control it, can you, the impulse to destroy? You want to kill your friends here too, don’t you? You want to string the boys up by their innards, don’t you? Rape the girls and then twist their heads off their shoulders? That’s the one problem with that sword… The demon ends up possessing the wielder, turning his soul murderous and dark. Don’t worry, Guren. Killing these five should temporarily quench the sword’s thirst for blood. Afterward, we can search for a way to control the cursed gear together. If we work together, I’m sure the two of us will be able to perfect this power. No one will be able to stand against us. No one will ever get in our way again. For now, all you have to worry about is killing them. Take the next step forward, Guren. Claim your power."

- Mahiru telling Guren to lose his humanity.

"Heh… You always were dashing, Guren. I wish I was the kind of girl who could be swept off her feet like that. I wish I really could just go with you. I know I’d be so happy if I did."

- Mahiru to Guren.

"Ha! Pretty words. But are words all you’ve got to persuade me? What about strength? Why don’t you just knock the sword out of my hands, grab me in your arms, and make me listen to you? That’s right. Because you can’t yet, can you? I’m so much stronger than you that it’s almost heartbreaking. I guess that’s what makes me the hare. Hurtling headlong toward destruction. I’m still waiting for my tortoise prince, Guren. Try and save me if you like, before it’s too late."

- Mahiru to Guren.

"In the end, you’ll fall. Your heart will grow black and twisted, just like mine. Do you see, Guren? We just can’t stay apart. We’ll keep each other company on the road to hell."

- Mahiru to Guren.

Catastrophe at Sixteen, book 3
Quotes from Catastrophe, Book 3 "My heart already belongs to somebody else. There’s no room left for you. That’s what I came here to tell you today."

- Mahiru rejecting Shinya.

"Ahaha. All I ever wanted was to have a normal life… To be a normal girl who can fall in love with anyone she likes."

- Mahiru to Shinya.

"Hmm… I’m not sure. But whether Guren is strong or weak, my feelings for him won’t change."

- Mahiru to Shinya when he asks if Guren is as strong as she is.

"Yes…I had to call now…while the demon part of me was still asleep…"

- Mahiru to Guren.

"I want… I want you to kill me… I’m in control of myself less and less every day. I’m barely here at all anymore. It has to be now, before it’s too late… While I can still resist—"

- Mahiru to Guren.

"G-Guren. […] I love you, Guren. […] Please, let me die while I’m still capable of feeling this…"

- Mahiru to Guren.

"I’m not human anymore, Guren… You can’t hold me. I’ve lost that right. I can’t be with you any—"

- Mahiru to Guren.

"You…don’t love me, do you? Of course, you don’t. It’s been ten years, after all… I’m not even human anymore… How could…how could anyone love a vile monster like me?"

- Mahiru to Guren.

"Please, Guren… I want you to take me… Will you sleep with me? Even if I am a monster?"

- Mahiru to Guren.

"I don’t know… I don’t know anything, anymore. I’m just so… so tired—"

- Mahiru to Guren.

"Yes, I have. I ate Shinoa’s demon. I was so desperate to save her that I swallowed it up whole. But that turned out to be my downfall. Once I had two demons inside me, I couldn’t hold myself together any longer. Still… I might be broken, but I don’t think I’ll forget what we did today. I love you, Guren. And I thank you. You finally gave me what I wanted. Thanks to this…the last bit of weakness left in my heart has finally died. Mahiru, the pathetic little six-year-old girl who called you on the phone to cry about how much she loved you, has let go of her attachment to this world and passed away."

- Mahiru to Guren.

"I’m sorry for getting you wrapped up in all of this, though, Guren… I managed to get the demon out of Shinoa, but in the end I wound up splitting it with you. Now, you’re going to become a demon, too. I guess I still wanted to depend on you a little…"

- Mahiru to Guren.

"I already told you, the world is going to come to an end. It’s exactly what it sounds like. The adults will be destroyed first, because they’re the most tainted and filled with desire. When it happens, everyone in the world over the age of thirteen will die… God is angry. At us, for our greed. At mankind’s vile nature and insatiable desire. At the unspeakable research we’ve been pursuing. The land will rot. Monsters will roam the Earth. Poison will rain from the sky. The Seraph of the End will blow its trumpet, and this world will fall. Mankind won’t be able to survive in the new world. Not the weak, at least."

- Mahiru explaining how the world will end to Guren.

"Come, Asuramaru…"

- Mahiru summoning Asuramaru.

"It looks like it’s started. Until yesterday, I was the only hare in the race… but things are going to change today. Everyone will need to become a hare. Everyone in the world. Make haste, make haste."

- Mahiru to Guren.

"I’m trying to be with you, Guren. To live with you, even if it’s in the next world. Even if it’s in a world where mankind can no longer survive. But for that to happen, we’re going to have to be demons."

- Mahiru to Guren.

"Haha. Look at how vile humans are. Give them the slightest reason to doubt, and they tear each other’s throats out. Is that the side you want me to join?"

- Mahiru to Guren.

"There’s one thing I know, though, Guren. You’re strong. Very strong. That’s why I love you. Kureto can’t hold a candle to you. If you ever get serious, the whole world will tremble at your feet. Because human strength lies in naïveté, weakness, and vileness. A demon’s favorite things."

- Mahiru to Guren.

Seraph of the End 4: Guren Ichinose: Catastrophe at Sixteen
Quotes from Catastrophe, Book 4 "Ahaha. I love how you try to protect these humans, Guren. I love how greedy you are. How you try to have it all, and in the end wind up with nothing. I love you so much, I want you to have even more of the demonic poison!"

- Mahiru to Guren.

"That doesn’t matter. What’s important now is that my brother, Kureto, is about to bring the cursed gear project to nearly 90 percent completion. He’s going to create an antidote to save you. People will be able to use it to wield cursed gear while still holding onto their sanity… But greatness requires more. Any plan put together by a rational person like my brother will always include a large margin of safety. An approach like that will never aim high enough."

- Mahiru to Guren.

"Kill me, so I can live on inside of you forever."

- Mahiru to Guren.

"This makes me love you even more…but I’m afraid a lovers’ suicide is out of the question. I’m entrusting the future to you. When everything is in hopeless ruins, I want you to be the last ray of light shining on the world."

- Mahiru to Guren.

Seraph of the End 5: Guren Ichinose: Catastrophe at Sixteen
Quotes from Catastrophe, Book 5 "You look human to me."

- Mahiru to Yūichirō Amane when he says his parents called him a demon.

"I am… I have my own battle to fight, so you’ll have to stay strong on your own. You do that, and someday I’ll come back to let you out of there."

- Mahiru to Yūichirō.

"I don’t think any human living is worth anything. No one is really important. Everyone is just a cog in the end. Get rid of this or that cog, and the next one will be born soon enough to take its place. But tell me, Yu, if there’s no real meaning or value to life, what will you live for?"

- Mahiru to Yūichirō.

"Ahh, you’re so adorable, Guren. Even in the situation you’re in, you still don’t know what to do. You want to be kind to everyone. You’re exactly the type of person who’s bound to turn to your demon for help. And you’ll fall so much deeper, so much darker than I did. You pretend that you’re good and just, but someday, when hope is gone and the future is lost… Ahh, I can’t wait, Guren. I can’t wait to see that happen. But I think we’ve talked enough for now."

- Mahiru to Guren.

"I don’t know what it’s like to be loved by your parents, so I don’t understand that feeling."

- Mahiru reflecting to what a child said about thanking her parents back when she was little.

"You think so? Maybe I’m just patient. My dream, actually, is to be a nice, traditional housewife. Long-suffering, you know?"

- Mahiru to Krul Tepes.

"Ahh, I can hear it again, that noise. Tock. Tock. The sound of desire. The footsteps of destruction. Someone cries out. Man’s sins are too great. Someone cries out. Man’s pride has grown too large. Like Icarus. Like Babel. The second hand continues to race. Avarice marches onward. Toward the end of the world. Toward a world of blood. This is the story of how man goes extinct once more."

- Mahiru to Krul.

Seraph of the End 6: Guren Ichinose: Catastrophe at Sixteen
Quotes from Catastrophe, Book 6 "Not that I really qualified as human even before becoming a vampire."

- Mahiru to herself.

"Are you that scared of me?"

- Mahiru to Guren.

"I came to protect what’s dear to me… You… and my sister."

- Mahiru to Guren.

"I’m still in the lead, Guren. But you’ve gotten very close. Hurry now, catch up to me and take me in your arms."

- Mahiru to Guren.

"Before we go any further, I need to tell you why I’m here. I’ve placed the cursed gear I dropped earlier, Shikama Dōji, in your pocket. Give it to Shinoa. As long as she has it, she should be able to survive after the world ends…"

- Mahiru to Guren.

"Ahh… I love the way you smell, Guren. I wish we could stay like this forever."

- Mahiru to Guren while wrestling with him.

"Ahhh, I can’t hold back any longer. Just a little, Guren, just a little taste."

- Mahiru to Guren before biting him.

"You see? You haven’t caught up yet, after all."

- Mahiru to Guren.

Seraph of the End 7: Guren Ichinose: Catastrophe at Sixteen
Quotes from Catastrophe, Book 7 "Don't move, weakling."

- Mahiru to Kureto.

"If you give up so easily, our dad will get mad at you again."

- Mahiru to Kureto.

"Don't look down on yourself Kureto. You're a much better person than I am."

- Mahiru to Kureto.

"Treat Guren well, Kureto."

- Mahiru to Kureto.

"You blockhead. My adorable, slow Guren, still for the tortoise. The world's going to end. There isn't going to be a next time."

- Mahiru to Guren.

"Even though it's too late now, I just wanted to hear your voice."

- Mahiru to Guren on the phone.

"Living until today meant something because you where there."

- Mahiru after thanking Guren.

"I love you, Guren."

- Mahiru to Guren.

"I'll ask you one more time, Guren. What's the point of living?"

- Mahiru to Guren.

"But I love you because you won't do that. I love you because you can't do that. It's just as Shinya said. If you did, I'd lose interest in you, I'm sure."

- Mahiru to Guren.

"No. You've already saved me. By coming for me in the end, you saved me."

- Mahiru to Guren.

"No. That's not it. I was bound to die embraced by my dear prince. That was my fate."

- Mahiru to Guren.

"I was so beautiful that I made a goddess jealous, and she tried to bring me down to hell...but my prince wouldn't let that happen and held me in his arms."

- Mahiru to Guren.

Seraph of the End: Vampire Reign
Quotes from the Owari no Seraph manga, the first entry in the series. "Silence, demon."

- Her order to Noya after swinging a sword at his mouth for encouraging Guren to spill sensitive information.

"Aww Don't you remember me? From the prison? You were five. They called you demon spawn. Your own parents even tried to kill you. A poor little monster, all lost and alone, with no reason left to live. Well, little monster? Did you find a new reason?"

- Both remembering Yu and recalling their conversation about his circumstances.

"Don't worry, little demon. You like human desires, right? So eat my desires... ... And grow even stronger."

- Whether she was speaking to Noya or Guren it was the latter she injected before growing two horns as she said this.

"Because I used a special spell to turn myself into a demon instead of being created the normal way."

- Answering why she has her memories when demons lose theirs.

"Well I am already dead, y'know."

- Her answer to the poisons she is injecting into herself.

"Ah. Once, then. One more clash, and we've won."

- Hearing about Guren's speed, Mahiru feels they can win (one more clash would not be enough though, so Mahiru's estimate was off.)

"I don't really see a point to losing, to be honest."

- An attitude to losing.

"After coming this far... ...Do you really want to lean on him? Do you want to give in... ...And acknowledge his feelings for you?"

- Raising how Guren regards Yu.

Trivia

 * The name Mahiru means "Midday" (真昼).
 * Mahiru's surname Hīragi means "Holly" (柊).
 * Mahiru is the only character known so far to be a demon who is possessed by another demon and it is almost as if the demon itself replaced Mahiru completely, besides her appearance.
 * Asuramaru and Shikama Dōji (Mahiru's demons) are currently in possession by a male and female lead of the manga series.
 * According to the light novel, Mahiru and Shinoa Hīragi were born with demons inside of them.
 * In the popularity poll, Mahiru earned 8th place at 957 points.
 * If Mahiru were alive, she would be 24 years old.
 * Mahiru's desire before her death was to become an ordinary girl, to love a favorite person and to give birth to a child.