Mikaela Hyakuya/Relationships

Mikaela Hyakuya experienced abuse and neglect from his parents before being placed in the Hyakuya Orphanage with other children when he was younger. Meeting Yūichirō Hyakuya he would consider members there his family, something that maintained when transferred to an underground vampire city. Due to Ferid Bathory, he would witness those he cared about be systematically slaughtered before he was forcibly turned into a vampire by Krul Tepes. His thoughts of finding Yu again would sustain him over years. On account of his knowledge of Guren Ichinose's background and his actions towards others, Mika would distrust and be hostile to him. Whilst Mika rarely interacted with other vampires he would come across them and various other characters throughout the Seraph of the End series, which affects himself and the story. This article details Mika's relationships with other characters.

Hyakuya Sect
Unknowingly involved with the Hyakuya Sect, of which his surname is from the organization, Mika would be experimented on by them. Sent to one of their orphanages, he was acquainted with Saito who led the sect. Mika would also meet his orphanage family, including Yu there.

Yūichirō Hyakuya
At eight years old when Yu first arrived at the orphanage Mika greeted him and was not discouraged from Yu rejecting his friendship. With Yu's anger heading towards violence Mika beat him up right after they met. Mika was understanding and assured Yu that things would become better from that day on. Together, they helped look after younger orphans in the vampire city as well when they were taken underground. Mika would show concern for Yu when he came into conflict with vampires and make an excuse for him so he did not have to go to Ferid's mansion. When the escape from the city was revealed as a trap Mika was calm as he reminded Yu to not forget they were family. In order to give Yu a chance to escape, Mika sacrificed himself and was fatally wounded but was happy to think he could pass away knowing that Yu had made it. As the last surviving member of his chosen family Mika is exceptionally protective over Yu, and saving him is Mika's sole reason for living. He means to rescue Yu from humans he has been told are manipulating him.

"Yu, I'll come save you."

- Mika to himself in Sanguinem.

Mika was startled at seeing Yu again for the first time in four years at Shinjuku to the point of physical inaction. When an opportunity arose Mika carried Yu away from the fighting and tried to persuade him to leave everything behind and escape with him whilst there was still time.

"I'm your only true friend! I won't try to deceive you! Those humans are only trying to use--"

- Beseeching Yu to escape with him out of concern he is being used.

Mika felt his concerns regarding human experimentation were realized after witnessing Yu transform. Unable to regain him and having to retreat Mika was extremely reluctant to leave Yu behind. Seeing him again caused Mika to shed tears for the first time since becoming a partial vampire. At Nagoya Mika would question Aiko Aihara for news on Yu's whereabouts as he searched for him. Spotting him amongst the retreating members of the Moon Demon Company Mika seized the chance to gain Yu and charged through the entire gathered squadrons to reach Yu at the back. Physical injuries from many soldiers including the strongest members did stop hinder Mika's determination to get Yu again. After getting him to safety Mika's idea was to tell Yu what he knew of their background but would not drink blood and become what he knew Yu hated the most.

"Yu... stay back. I don't want to drink your blood."

- Meeting him a second time, Mika focuses on not drinking blood that can save him.

At last persuaded Mika would drink his first human's blood, that of Yu's which made him a complete vampire with red eyes. Whilst Yu was set on rescuing his squad Mika attempted to get Yu to listen to him.

"I will do whatever it takes to protect you. And to keep you out of the hands of the Japanese Imperial Demon Army. They've used people like us for years, Yu. Used us in their experiments. I'm sure that Guren person didn't save you and take you in out of the goodness of his heart. We're part of the Seraph of the End Project—"

- Committed to defending Yu, from the army he is a part of, and those he believes he is close to.

While Mika asked for Yu to run away with him where they could live together, he agreed to check if his squad was okay first. Mika would stand back to back with Yu at Nagoya airport when human soldiers were being massacred. He would then defend Yu from Guren and help in the brief fight against him.

"You're the one who keeps insisting you'll turn me back into a human someday. Where do you get off letting yourself get turned into something inhuman too? You just had to go and protect those stupid humans, didn't you? Now you've done irrevocable harm to yourself!"

- Bickering with Yu and more concerned for him.

After escaping, Mika would keep watch over Yu with him being the only one he trusted. Whenever Yu is involved on the battlefield, Mika becomes reckless. When injured by Fuola Honte, Mika ha no concern for himself rather he told Yu to stay back to keep him away from danger. After seeing his actions Mika is willing to kill Guren despite Yu's heavy protests that he is also family. He is willing to eliminate Guren as a threat even if Yu hates him for it. Although sometimes Mika finds it hard to emphasize the dangers that he sees Yu as being oblivious to Mika is patient in explaining them but will also take action if it takes too long. In chapter 55 Mika holds Yu's hand to comfort him after they see the deceased members of their family again.

"What the heck, Yu?! Why're you suddenly trying to keep secrets from me?"

- Mika to Yu

Mika was concerned for Yu's wellbeing when he wanted to save Shinoa and tried to persuade Yu to not give away information for free to Kureto. Mika was also somewhat distressed at Yu offering his memories for experimentation. With Yu led away and with him captured by the Hyakuya Sect Mika remained unwaveringly committed to locating him amongst the chaos breaking out across the city with the first present and an invasion occurring.

Mika's dedication to being there for Yu would pay off as he would be the first to successfully locate Yu. After cutting him loose Mika was ready with Yu to fight against Guren as a demon, Mahiru and Noya. With Yu convinced Guren was still their friend Mika changed tactics to convince Yu he needed to take part in a pre-arranged plan, one that involved them escaping. During the fight they kept close together and Mika took a hold of Yu and used his own body to defend him from Guren's sword. Worried about Yu having to draw upon more demon power, Mika would try and pull him from the ceiling for them to escape.

"Uh, you do realize you just grew horns, right? Are you okay? You aren't going to go berserk on me, are you?"

- Concerned with Yu's transformation into a demon

With Yu's safety at risk Mika largely sacrificed himself to fend their enemies off. In chapter 90, Mika would see Yu upset far below as he was lifted into the sky and after saying for him not to cry Mika told Yu that he loved him.

"Yu... I love you."

- Mika's feelings.

After entering the dream world, Mika sees Yu along with the rest of the children, but he always distinguishes Yu among them. Although this is an illusion, Mika is happy that he and Yu can be with the rest of the children and live in peace. Before bed, Mika talks to Yu and remembers that he was aloof from everyone, but now he takes care of everyone. Mika begins to tease Yu and says that now they are like parents to everyone. Mika ponders how good it is to be together. Although the others will go their separate ways, he and Yu will always be together after years. When Yu says that he is happy that he especially met Mika, Mika looks upset as he realizes that this is an illusion. Although Yu's illusion tries to convince him that everything is fine, Mika begins to cry and says that he tired. But Mika, in the end, still remains to live in the world of dreams with Yu. Mika continues to live with Yu's illusion even further. They have a cup of noodles together while the rest of the children are asleep. During Asuramaru's attack, Mika defends Yu.It is shown that Mika always blamed himself for the deaths of children and thought Yu blamed him too. When Mika comes under pressure from Asuramaru to kill the children, Yu was the one Mika called. While killing Yu's illusion, Mika apologizes to him numerous times.

Later, Mika accesses Yu's heart. He is surprised when he sees a big eye, but realizes that it will not harm him. Mika wants to know more about Yu, so she goes back in time. He sees the cycle of Yu's life, which was born and died constantly at the hands of Noya. When Shikama attacks Mika, he hears Yu's voice. As a result, he decides to become Yu's demon.

During their battle with Shikama Doji, as drawing upon Yu's desires also bought his memories along with them, Mika could remember his own feelings and memories from their connected event. Back as himself, Mika chided Yu for wanting to die when he escaped as a child.

"I peeked into your memories! That's totally unacceptable! If you had died, what would have been the point of me throwing away my life to save you?!"

- Answering Yu's question, and saying it was unacceptable that Yu wanted to die after he escaped Sanguinem.

Resolving to protect Yu, Mika is comfortable with exploring his newfound demon capabilities with him. Contacting Yu privately, Mika would share his concerns that they are being used by Guren along with Mahiru, also Ferid and Krul.

"What are you doing? Now is not the time to be having a fun chat with friends!"

- Contacting Yu in their sphere, alarmed that he does seem to register the state they are in.

With conflict arising, Mika would draw upon Yu's desire to enhance the sword's power. Alerting Yu to poison, and feeling his desire to surpass Guren, he resolved they could do this and Mika would help him win. When Yu learned that Guren had a hand in the deaths of their family, Mika did not consider his own thoughts but checked on how Yu was holding up instead.

When there is apparently a chance to restore his humanity, or resurrect the fallen humans, Mika tells Yu he is for the latter. Shocked when called as a weapon, Mika complies but from the sword he seeks to calm Yu. Reminding Yu he is pointing the sword at his family, Mika assures him he is still that to him as well. Listing specific people such as Akane being resurrected, and what Guren has undergone, Mika attempts dialogue with Yu to guide him into accepting the human resurrection course.

Sure that he could make the choice, Mika then shares how important Yu is to him. Where Mika spoke from a distance how he loved Yu before, he mentions how it was specifically him, rather than the family at large, that made him believe he could do anything.

"Back then I was full of dreams. As long as I had my family... Well, no. As long as I had you... ...I thought I could do anything."

- Emphasizing Yu's importance to his own dreams.

Appearing happy yet tearful at the same time, Mika also shares with Yu his inner guilt at feeling responsible for the deaths, a pernicious feeling that he had kept inside to himself for a long time. Both because of a genuine feeling that he was responsible for their deaths, and to press Yu to head on the path, Mika spoke that he wanted Yu to save his heart which could be done by bringing Akane and the kids back.

Having him comfortable given difficult topics, Mika told Yu he was sorry that he had to go through this as he eased him. In mentioning how everyone dies eventually, Mika states but then they get to be together in heaven. Encouraging Yu to go ahead with resurrecting their family together, and seeing him cry, Mika assured him it would all be fine, and they will be together forever.

"It'll be okay, Yu. It'll all be fine. We'll be together forever."

- Assurances given since Yu is crying, and his future ideal plans.

Shocked at Yu suddenly needing all the power ever, Mika was against this action and called for Yu him to stop as he became a demon. Speaking with him, Mika raised with Yu how he had turned his sword against his family. While Mika did not support Yu attempting to escape them, and apprently did not favor him fighting Asuramaru, he would still not have Yu lose or have him compromised. After the incident, Mika was not exactly talkative and was concerned at the path Yu was heading down. Regardless, he still unhesitatingly assisted Yu when he requested help. Hearing Yu speak of caring for family, Mika reciprocated where his reply concerned solely Yu and his happiness.

"Me too, Yu. If you're happy, that's all I need. Your happiness... ...Is my happiness."

- Agreeing with Yu's goal of saving family, and heavily focused with his happiness.

After escaping, he would wonder what his plan of action was given they were being chased. Even in such a state, and when alone with Yu where in the past it was what Mika desired, at this point Mika has Yu's happiness in his mind foremost, and sees his return to his squad as the means to achieve that. Together they both express their deepest feelings. With tears in his eyes, Mika asks Yu to leave him and continue to live, because everything ended for them when Yu ran away and turned away from him. He also suggests that Yu find someone else to marry and have children, again mentioning Yu's obsession with him.

"Drop your stupid obsession with me already! Don't cling to the past! It's over! Gone! It all ended that day! That day... ...You chose to leave me behind and start a new life!"

- Part broaching the difficult topic that Yu did indeed leave him and start a new life, and part desire for Yu to return to his squad since Mika feels he would be happier that way.

This was done as Mika believed that Yu had left his squad who loved him where they were now alone together. The attempts to have him leave for his own happiness were met with Yu refusing to do so, combined with being able to sense his desires that he did not want to give up. Listening as Yu shares feelings that he was suicidal and there was no reason for him to live, after it is said that leaving him is like telling him to die, Mika becomes open to hearing what he plans to do. When Yu's plan became clear that he wanted him to find a way to acquire a more complete resurrection, Mika agrees to help.

Akane Hyakuya
One of the children from the Hyakuya Orphanage, Akane was younger than both Mika and Yu, but she was at the orphanage longer than Yu. She was the third eldest and was kind and responsible. Mika would hand Akane the curry ingredients to prepare. She was the last person Ferid Bathory killed when Mika's family tried to escape Sanguinem in 2016. Ferid has since preserved her body and is holding it hostage, along with the corpses of the other orphans.

It was revealed that she had a crush on Mika as well although he did not seem to return the feelings. With the time passed, and the costs of human resurrection and that Mika has Yu he is not in favour of resurrecting the dead largely due to it being Guren involved with it and the technicality that Akane perished after the apocalypse event.

Akane was one of the children who lived with the others as an illusion of Mika's desires.

When Yu wants to restore him, rather than resurrect humanity, Mika mentions Akane in trying to sway him otherwise.

"Okay. So does that mean you're okay abandoning Akane? You're okay with abandoning all the kids who died? You'll bring me back... ...But you'll give up on Akane and the kids?"

- Questioning whether Yu is okay with not resurrecting their family members.

With Akane specifically mentioned, Mika is also himself in favor of restoring her among the rest of humanity.

Junji Haiyama
A boy living at the Hyakuya Orphanage with them in Shibuya prior to the apocalypse in 2012. Miyuki Yamada (Mahiru Hīragi) "adopts" Junji when he is four years old, and Mika has to calm him down before he leaves.

Yuki Endo
One of the children living at the Hyakuya Orphanage in Shibuya, Yuki stayed with Mika, Akane, and Junji back in 2012 prior to the Apocalypse.

Mahiru Hīragi
Mika and Mahiru first met at the shelter when she introduced herself as Miyuki Yamada. Although Mahiru said that she would like to take Mika and considered him an unusual child among the rest, Mika immediately did not trust her and did not want her to take the Junji. Mahiru herself realized that Mika could easily recognize her lies. Mika asked her many times if she would take good care of Junji and gave advice on how best to look after the boy and what books to read to him. Eventually, this prompted Mahiru to compare Mika's childhood with hers, and Mika gave her the Junji.

Both Mikaela and Mahiru were sired by Krul Tepes. He did not appear to recognize her when he was assailed by the spirit of Mahiru and the sword and spell tags she could use. Mika abandoned the battle with her in favour of rescuing Yu and would tell him she was trouble. As Mahiru along with Noya were the separated aspects of Guren's cursed gear weapon, Mahiru-no-Yo, Mika would fight alongside Yu against her.

Spotting her in the memory of Sanguinem, Mika would regard her as one of the shadow players whose plot they were caught up in. Questioned if he had seen her in the past yet, Mika asks who Mahiru is when the topic of past Yu's arises.

Saitō
The leader of the Hyakuya Sect, Saitō is a second progenitor vampire who has undergone extensive experimentation for increased strength and regenerative abilities. He gave Mika money for ice cream and things for the children and watched over them from time to time. In reality, he was actually a vampire. It dawns on Mika that he may have been manipulated by this seemingly kind person.

Vampires
Living as a human cattle in one of their underground cities, Mika thought to use his smarts to survive among them. When his family were murdered by Ferid, he spent years living amongst vampires and resented them for their actions.

Krul Tepes
A third progenitor, Krul is the queen of Japan. She is familiar with the seraph of the end. In 2012, Krul intentionally disobeyed orders to kill the Hyakuya orphans and rescued Mika's family by raising them as livestock in Sanguinem instead. Four years later, Mika would owe his existence to her a second time although now reluctantly and he was transformed into a vampire against his will by Krul. Whilst it saved his life Mika detested being anything related to vampires yet when he refuses to drink human blood he is permitted to sustain himself off of Krul's. Four years later Mika and Krul have a close relationship and she is the only vampire seen who he interacts without any ignoring as is the case with others. They are close enough that in a state of blood lust Mika can hoist Krul off her throne, drink directly from her neck then toss her aside once he realizes what he done. He checks first to make sure Krul has nothing negative planned for Yu then is entrusted with a sensitive mission. Mika is instructed to disappear during the war and find Yu after having her true agenda whispered to him. While Mika acknowledges that Krul may regard him as a pet Mika feels at least Krul will hear them out.

"Krul!! I want to save Yu! But... How can I do that?!""

- Turning to Krul

Seeking Krul's guidance on rescuing Yu in a battle zone, Mika would comply with her direction. When Ferid and Crowley ambush both Krul and Mika he complies with her orders that only he hears and rescues Yu before the humans.

Three months later with Yu's demon situation only getting worse and the squad deciding their options, Mika's unique input is for them to save the vampire queen, Krul from her imprisonment. Finding one another again in Osaka Mika and Krul's secret plan remains that and they pretend not to know one another around other gathered vampires to keep it that way. Along with the rest of the squad they mean to rescue Krul as their best course of action.

When Asuramaru says his real name, Mika remembers Krul who has the same. It was revealed that Krul was the one who trained Mika to fight. Although Mika lost to her, he still asked to teach him more.

After returning as a demon, Mika is pushed over by Krul. Where she is supposedly doing him the honor of checking how powerful he has become, Mika is on the ground as he asks whether she means to compliment him.

"Your clan, huh. And does that mean you love me?"

- A question for Krul after returning as a demon.

Where Krul says she cannot say what love it, Mika moves to speaking candidly on what she really wants. Requesting that there be no secrets, Mika hears Krul wants her brother back. Heading to a location with Guren, and seeking to acquire what information he can considering nothing is known, Mika engages with Krul.

"Hey, Krul? Did you come along with us... Because you and Guren have a mutual interest?"

- Attempting to gain information given that they are with Guren.

Hearing yes, Mika then ascertains whether Guren and Krul have a deal with Ferid. Asking her directly, Mika questions whether Krul's interests align with theres.

Ferid Bathory
Growing up in Sanguinem, Mikaela approached Ferid and was friendly to the vampire noble. In exchange for letting Ferid bite him and drink his blood, Mika received money and good food that he shared with his orphanage family. With Yu wanting to leave the city Mika's true goal was to steal a map, and he succeeded in stealing both that and a pistol from Ferid's mansion. However, Ferid waited for them at the exit and slaughtered the Hyakuya orphans. By sacrificing himself, Mika was able to give Yu the opportunity to escape, but Mika was fatally wounded by Ferid and without intervention would have likely passed away from the injuries to his arm and body. Once Mika is a vampire he spends four years living with the individual who betrayed his trust and murdered those who he held dear. Mika largely ignores Ferid, he will walk away when he notices him yet will point his sword at his neck in private when approached. To not give Ferid any satisfaction Mika states that he is only angry at himself for leading his family into a trap he knew nothing about. After grabbing him by the throat and saying he will kill Ferid if he turns Yu into a vampire Mika whimpers when Ferid places his hands on him. As before he is dependant on how Ferid can practically help, from providing information to rescuing Yu for Mika. He is content to have Ferid's assistance in such cases but Mika does cut off Ferid's arm on the battlefield when he touches Yu. Against Ferid from hassling children in Sanguinem Mika was invited to the progenitor council meeting where his presence was used to make Krul feel uncomfortable in front of other ruling vampires.

With Ferid sighted again Mika advised the squad that Ferid could not be trusted. Whilst he attempted to remain calm and focused on having Yu the same Mika was furious after Ferid bit Yu and drank his blood and said he would never forgive him.

"You bastard. I will never forgive you for this. Ever!"

- To Ferid after he bites Yu.

Where there was little choice but to go along with Ferid's plan, Mika shared details to others on him.

"You don't understand. Ferid is manipulating all of us into thinking what he wants us to think. We're already completely caught up in his little games.... Yes. And he's an eccentric too. He's the last person anybody wants to get involved with."

- Informing Shinoa Squad.

After acquiring a sinful key Mika was ordered to hand it over to Ferid or he would have all his clothes stripped off with unspeakable things done to him. Handing it over Mika questioned what Ferid was up to this time to maintain some semblance of control. Mika cannot do much against someone who has inflicted such deeply sorrowful experiences on him whether due to a lack of strength to internalizing the trauma then needing Ferid for the information he knows.

Lacus Welt
He is a city guard that often works with Mika and René. Mika's power impresses Lacus, but he is concerned about Mika not drinking blood, considering him weird for not doing so. He is chatty and often tries to start conversations with Mika, but Mika usually answers with silence. Lacus says he does not care whether Mika lives or dies and for his part Mika is indifferent to this indeed most of the views from Lacus.

René Simm
A coworker in missions including destroying Four Horseman of John to secure their human food supply. Mika is accused of stealing glory by René, but Mika is uninterested. He is quiet and more serious than Lacus. If no one outranks him, he will direct the two of them on the battlefield. Unlike Lacus, he is unconcerned with Mika's odd behavior so long as Mika does his job.

Crowley Eusford
On the same battlefield in Shinjuku as Crowley Eusford, a thirteenth progenitor, his arrival would help with Mika being able to rescue Yu. Coming into contact again, Mika would discuss with Yu how the squad could not defeat Crowley, so offered a truce and talk. Travelling together, Mika would remain by himself while Crowley drank blood from a glass. They discussed Ferid's possible plan.

"Now that he's played with our emotions, he'll plunge us into despair so he can amuse himself with our tears. Right?""

- Speaking to Crowley about Ferid.

Where Mika also asked Crowley about when his emotions might fade when that was a concern. Battling alongside one another against Ky Luc, they are also in the same group involved with Guren's plan of resurrecting humans.

Humans
Where Mika was a human himself he was lively and friendly with all, even those who were not overly polite with him such as Yu when they first met. As a vampire, Mika is tasked with fending off Horsemen from them, to gathering, both for the wider purposes of vampires retaining a blood supply. For their human experimentations, Mika would come to harbor resentment against them.

Shinoa Squad
Seeing them, Mika was not surprised that Yu had made new friends, but regarded his squad as manipulating him. In coming close to members, Mika would only be concerned with Yu's wellbeing. In a tight spot, Mika knocked members aside to reach Yu yet would experience a change in perspective on family defending one another upon being protected by them. While not overly talkative around them when they combined as a group, Mika would share his thoughts on potential pathways they could take, and share his opinions.

How he would come to see the squad would be displayed when Mika thought Yu would be fine with them. Seeing that they were coming to retrieve him left Mika assured Yu would be okay even if he was gone. Although Yu was far closer to Shinoa squad, it is Mika who points out how he is acting around them. When Yu means to escape, Mika chides him for turning his weapon against his family. Where Yu's happiness was concerned, Mika would go so far as to order Yu to leave him and return to a family who he knows loves him.

"And that Shinoa girl. Do you remember what she said at the end? Yoichi too. And Mitsuba. And Kimizuki. At the end... ...They all said they love you. They begged you not to go. You must've heard that."

- Reminding Yu of the concern his squad had for him.

Shinoa Hīragi
A sergeant of the Japanese Imperial Demon Army's Moon Demon Company. Shinoa first met Mika when they were eight years old while she was delivering messages from her sister, Mahiru Hīragi, to Guren. Eight years later, they meet on the battlefield, and Yu considers her to be a friend. Mika nearly died protecting her from Yu in Shinjuku for that reason, but claims she is just using him.

"Shut up, Human. I didn't do this for you. How dare you use him like this!"

- Speaking to Shinoa in Shinjuku, after he just saved her life.

She returns the favour in Nagoya when she defends Mika from her compatriots in the Moon Demon Company and even attacks Major General Shinya Hīragi to save Mika's life, and labelled as a traitor as a result. She allows Mika to escape with Yu and tells him to meet up with them at the Nagoya Airport later on. Thanks to her intervention, the rest of her squad joins her, and Mika is able to flee with Yu. By the time the battle in Nagoya comes to a close, Mika leads Shinoa and the rest of the team to safety, away from both humans and vampires.

Shinoa and Mika continue to communicate after escaping. Shinoa offers Mika the blood of the squad, but he repels it, since he does not want to be the pet of a woman. He distrusts Shinoa and thinks that she wants to use Yu. But Mika still begins to trust her a little. When they arrive in Shibuya, Mika is interested in her past and her family, although she says that she does it only for Yu's sake. When Shinoa turns into a vampire, Mika considers the option to save Shinoa, but quickly pushes this idea away and realizes that it's too late to save her. Shinoa was one of those Mika saw before dying, thereby showing his confidence that he could rely on her to protect Yu.

Aware that Shinoa loves Yu, he encourages him to return and learn to like her back. Referring to her as that Shinoa girl, Mika thinks of her when feeling that if Yu made a family, and had kids together it would make him happy.

Mitsuba Sangū
One of Yu's squad members, Mitsuba defends herself from Mika when he tries to reach Yu, after he had just fought his way through an entire regiment, but Mika knocks her aside. After Shinoa protects Mika and tells him to escape with Yu, she stands beside her to defend him from their own army.

They get along well after Mika escapes with the rest of the squad. Mitsuba was shown helping Mika when he lost his arms to an attack. Mitsuba was one of those Mika saw before dying, thereby showing his confidence that he could rely on her to protect Yu.

Shihō Kimizuki
One of Yu's squad members, Kimizuki carries Yu on his back when Yu is unconscious in Nagoya and tries to prevent Mika from taking Yu. Mika headbutts and throws him out of the way. After Shinoa protects Mika and tells him to escape with Yu, he stands beside her to defend him from their own army. They begin to communicate well after escaping. He was also the one that Mika confides in Yu after his death.

Yoichi Saotome
One of Yu's squad members, Yoichi is the first one to recognize Mika in Nagoya and does not want to fight Mika. When Mika first grabs Yu, Yoichi jumps on top of him and hugs him from behind, saying that anyone who is Yūichirō's family is their family. Mika pushes him off and then tells him to not be stupid and to die. Thanks to his actions, Shinya Hīragi is able to stab Mika from behind, but Yoichi urges him not to kill Mika. After Shinoa protects Mika and tells him to escape with Yu, Yoichi stands beside her to defend him from their own army. They begin to communicate well after escaping. He was also the one that Mika confides in Yu after his death.

Makoto Narumi
The sergeant and leader of his squad in the Moon Demon Company. In Nagoya, Narumi squad fights against Mika first. After Rika and Taro block Mika's attack, he makes the first offensive strike against Mika, but Mika blocks it. Mika runs past him and his squad to reach Yu. Makoto is baffled and comments that running into the middle of their company is a stupid move. After Shinoa and her squad protect the vampire from the Moon Demon Company and let him escape with Yūichirō, Makoto follows Shinya's orders to not kill Shinoa and protects her from another soldier. After this, he sees vampires kill two members of his squad.

After escaping, Narumi and Mika do not get along well. Narumi distrusts Mika due to the fact that he is a vampire, and also because of his fault, his friends died. Mika also distrusts Narumi as he thinks he is using Yu. But the two find a compromise when they arrive at Ferid's mansion and start getting along.

Guren Ichinose
Currently the leader of the Moon Demon Company in the Japanese Imperial Demon Army. Mika was eight years old when he first meets Guren in the light novels. When Mika asks about him, Saitō of the Hyakuya Sect says that Guren is a pervert. When they meet again on the battlefield eight years later, Mika doesn't consider him very strong and defeats him with some help from Ferid and stabs him through the chest with his sword, making him cough up blood. In exchange, Yu goes into a rage and stabs Mika before recognizing him. Yu cares about him. This person is responsible for Yu's transformation in Shinjuku, and he has been collecting and experimenting on the seraph of the end.

"Shut up. If you're aware of the atrocities you've perpetrated, then get lost. Leave and never come near Yu again."

- Whilst others are pleased that Guren has returned Mika is anything but

Mika doesn't trust Guren. He is sure that Guren is just using Yu. When Guren returns, Mika takes it negatively. He accuses Guren of killing the whole world and they live like this because of him. Eventually, Mika and Guren start to fight. They again get into a skirmish in Shibuya. The first time Mika wanted to take Yu and run away, Guren stopped him. Mika was convinced that Guren was Shikama's dog and ended up fighting until Shikama's arrival left them. During the second battle, it turns out that Mika also needs to Guren no less than Yu. They fight again, as a result of which Mika perishes at the hands of Guren.

In exploring Yu's memories, Guren is in mind as Mika seeks to understand what he means to him. Seeing how he is regarded as Yu's saviour, who helped him when he was alone, Mika wonders whether it is a good idea to trust him.

"All those years... Yu suffered, feeling alone and abandoned. His savior... ...Was Guren Ichinose. Aha. So that's what he is to Yu. Now that I've eaten Yu's memories, I get why he wants to trust him so much. But... ...Is trusting him wise?"

- Having viewed a memory of Yu training with Guren and understanding his significance, yet skeptical of whether he can be trusted.

Betting Guren has an ulterior motive, Mika considers he would not save Yu out of the goodness of his heart.

Returning, Mika does not speak only casts a glance to Guren. After he calls for them to trust him, Mika thinks to himself there is no way. Regarding Guren as one of the shadow players, Mika means to find out his plan before he can enact it.

Helping Yu in his fight against Guren, he feels his desire to surpass him. Mika resolves to help Yu win. Possibly knowing about it beforehand, when Guren reveals that he had a hand in the murder of their orphanage family members, Mika pays no mind to him but focuses on Yu's wellbeing instead. His opinion on whether he forgives Guren for his actions is not sought.

Reaching Akihabara where his family has been moved, Mika is apparently convinced that Guren has attained the means to resurrect them. His attitude concerning Guren having sharply reversed, Mika considers how legitimate his claims are and is apparently swayed by them as there seems to be the chance to restore their family. Also taking into account how Guren is against Shikama Doji, further consideration is given to what he has gone through which favorably shapes Mika's perspective of him.

"You know Guren went through hell to get this far. His enemy is the First himself. He has to have made a lot of hard, ugly choices. Today... ...Is your turn to make a hard choice."

- Taking into account what Guren has done, and encouraging Yu to follow that example.

It is Guren who Mika resorts to when attempting to persuade Yu to forget about changing him from a demon, and resurrect all of humanity instead. After the resurrection scenario became clear, this came with a sharp reversal in Mika's perspective of Guren. Both the plan of resurrecting humanity, and that he appears to like Yu seem reasons for Mika's change.

"Guren's trustworthy enough. Leave this to him. He likes you."

- Speaking with Yu and displaying a marked change in how Mika regards Guren.

Norito Goshi
A member of the Guren Ichinose Squad. Goshi works with Guren and Shigure Yukimi to fight Mika in Shinjuku. Mika is assailed by his illusions, though Mika was capable of dodging. In Nagoya, Mika is again affected with a powerful illusion, but Mika charges right through it, surprising him.

Sayuri Hanayori
A member of the Guren Ichinose Squad. In Shinjuku, Sayuri is fighting another vampire and is unable to help Guren fight Mika, but she warns him that taking a second tablet may kill him. In Nagoya, she is the first one to suspect Mika may have an objective aside from attacking them. She attacks Mika after he jumps out of Goshi's illusion, though his sword is enough to cause hers to break.

Mito Jūjō
A member of the Guren Ichinose Squad. In Shinjuku, Mito is fighting another vampire and is unable to help Guren fight Mika. In Nagoya, she punches Mika and knocks him out of the air after he dodges Sayuri's attack and gets hit by Shigure's kunai.

Shigure Yukimi
A member of the Guren Ichinose Squad. Shigure works with Guren and Norito Goshi to fight Mika in Shinjuku. She uses traps and daggers to attack. In Nagoya, she manages to work with her squad to fight Mika and throws three kunai into Mika's thigh.

Rika Inoue
A member of Makoto Narumi Squad. In Nagoya, Rika blocks Mika's first attack along with Tarō Kagiyama.

Shūsaku Iwasaki
A member of Makoto Narumi Squad. In Nagoya, Mika runs past Shūsaku before he can do anything.

Tarō Kagiyama
A member of Makoto Narumi Squad. In Nagoya, Kagiyama blocks Mika's first attack along with Rika Inoue. After Mika escapes, he is killed by a vampire after that vampire kills Yayoi, and he tries to avenge her.

Yayoi Endō
A member of Makoto Narumi Squad. In Nagoya, Yayoi is ordered to attack but Mika runs past her before she can do anything. After Mika escapes, she is killed by a vampire.

Japanese Imperial Demon Army
Warned of, and tasked with fighting against the Japanese Imperial Demon Army, Mika is particularly against them as they have the most involvement with human experimentation. His negative view of the largest and most ruthless military organization in Japan is reinforced at witnessing them murder their own troops to bring a seraph to the world.

Shinya Hīragi
A Major General. In Shinjuku, Shinya snipes once at Ferid. In Nagoya, he takes command of the Moon Demon Company after Guren is captured and leads the fight against Mika. After Yoichi jumps on Mika and calls him family, distracting him, Shinya stabs Mika from behind. Shinoa Hīragi attacks Shinya to prevent him from killing Mika. After she defends Mika and allows him to escape with Yuichiro, Shinya orders the army not to kill her. He attacks with Guren Mika later.

Aiko Aihara
A squad leader in Nagoya, after Aihara orders her team to commit suicide, Mika sticks his fingers in her mouth and removes the pill she was going to ingest. He tries to convince her pretend to be dead and even lies to the other vampires, stating that she is so.

"Shut up. Or the others will hear that you're still alive. Play dead. Speak in a whisper. Do that, and I'll let you escape."

- With other vampires around, Mika improvises with Aihara to learn where Yu is.

After she hears that the vampires are going to head to Nagoya City Hall, where most of her comrades are, she pretends to take Mika hostage and tells him Yūichirō's location. He works with her to deceive the other vampires into thinking that the Automobile Museum is the humans' target. Afterward, she insists that he kill her because suicide would look too suspicious, but he tells her to do it herself. She then attacks Mika, and with either a quick death or torture by other vampires as her fate Mika provides the former without ever learning her name. He looks slightly sad for a moment afterwards. She is the first person Mika is shown to actually kill.

Kureto Hīragi
The Lieutenant General of the Japanese Imperial Demon Army whose organization Mika has been warned about. Mika is not as aware of Kureto as other humans yet would still regard him as a puppet of the first progenitor when his presence became known. In a swift fight with Guren and Shinya, Mika would be struck by Kureto's cursed gear lightning with the moment brought to an end.

Demons
Although told by Krul there is a risk vampires can turn into 'ugly' demons, Mika does not majorly register the connection, neither makes no mention of these unseen foes within human cursed gear. When Mika became a demon without memories himself, he was targeted by them. Once his memories returned, unlike when Mika was a vampire and felt guilt about it, he makes no comment on his state as a demon and appears content.

Asuramaru
Unknown to Mika, while battling Yu with nightmares, Asuramaru often takes the form of Mika when he was twelve years old. When Yu was possessed Mika learnt it was Ashera Tepes and pieced together the demon's connection with Krul Tepes. Confronted by him physically in his dream world Mika regards Asuramaru as the demon he announces himself as and responds to his threats of death by charging at him with a knife. Mika stabs Asuramaru repeatedly and calls for the monster to die. He hears that his deepest fear and desire are the same, to be blamed for the deaths of his family. Mika has his body controlled by Asuramaru and is made to murder the other children including Yu that he was with. When Yu is battling Asuramaru, although Mika is not fond of Yu becoming a demon, and is said to not want him to win, Mika does not prevent Asuramaru from being vanquished.

Shikama Dōji
The first vampire, and currently the demon inhabiting Shinoa's scythe. Unknown to him, Mika was brought to a Hyakuya orphanage that Shikama Doji had secretively added to Saito's roster. Bearing a physical resemblance to his son, Mikaela from the ancient past, Mika is speculated to perhaps be a vessel to contain his soul.

Once in Shibuya, Mika can sense Shikama Dōji's presence and realizes that the place is dangerous. When Shikama wakes up fully, Mika says that although they have never met (as Mika thinks), he realizes that he became a vampire because of Shikama and calls him a monster. Mika is one of the important parts of Shikama's plan and is his experiment.

"Incredible. He’s awoken so many times. I’ve never met him personally, but somehow I can tell that that is the source of the stupid curse that made me what I am now. It’s a monster."

- Aware of Shikama Dōji's awakenings and thinking his opinion.

They face each other while Mika as a demon views a memory from the past. Although he does not have memories, Mika immediately realizes that Shikama is something bad. Sensed int he memory, Mika attempts to escape, yet is bound by the First's pressure and sleep based powers. Called by Yu, and becoming his demon, Mika helps attack Shikama Doji.

Noya Hienma
Mika senses Noya when he leaves Mahiru's body. In the Dark Ages of Greece there is seen a corpse of "Mikaela", Noya mentions whom what all of them were meant to become but failed. He along with Krul and Ashera were unsure what were they trying to do with it. However in the present time, Noya was surprised to see a "Mikaela" alive.

Mrs. Shindō
One of Mika's parents, after joining a religious cult, she becomes delusional. She tells Mika that he has a special name and is a good child but never stops her husband from beating him. While Mr. Shindō speeds down the interstate one night while drunk, she pushes Mika from their vehicle and tells him to jump, ignoring his begging. Ironically, he sustains severe injuries but survives while his parents shortly die in a major car accident immediately after.

Mr. Shindō
After Mrs. Shindō begins to lose her sanity, he begins drinking alcohol and becomes an alcoholic. He beats Mika every chance he gets, and Mika constantly tells him he loves him to try and make the beating stop. It is ineffective. Speeding while drunk makes him have a car accident that kills both him and his wife.