Mikaela Hyakuya/Relationships

Mahiru Hiragi
A teenage girl who used the alias of Miyuki Yamada while interacting with the Hyakuya orphans. She "adopts" a 4-year-old boy named Junji and claims to accept him as part of her family while actually using him for experimentation.

Eventually, she turns into a demon and is sealed within a sword used by Guren Ichinose.

Akane Hyakuya
One of the children from the Hyakuya Orphanage. She 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. She was the last person Ferid Bathory killed when Mika's family tried to escape Sanguinem in 2016.

It was revealed that she had a crush on Mikaela as well.

Yūichirō Hyakuya
Formerly a member of the Japanese Imperial Demon Army and one of the seraph of the end. As the last surviving member of Mikaela's orphanage family, Mika is extremely protective over him, and saving Yu is Mika's sole reason for living. Yu arrived at the Hyakuya Orphanage shortly before the Apocalypse virus swept through Japan. Mika beat Yu up right after they met, but they eventually became best friends. After the apocalypse, the vampires swiftly took them underground. Four years later, they tried to escape with their family, but Ferid Bathory killed the rest of their family in front of them. In order to give Yu a chance to escape, Mika sacrificed himself and was fatally wounded. Yu fled to the surface, and Krul Tepes turned Mika into a vampire soon afterward in order to save his life.

Unfortunately, Guren Ichinose picked up Yu on the surface and has been experimenting on him to use as a weapon. Whenever Yu is involved on the battlefield, Mika becomes reckless. Yu stabbed Mika twice since he became a vampire, but Mika will risk his life for both Yu and Yu's so-called friends. Mika finally manages to escape with him in Nagoya.

Saitō
He is a member of the Hyakuya Sect 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.

Krul Tepes
A third progenitor and 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, she transforms Mikaela into a vampire against his will, effectively saving his life and preventing Ferid Bathory from becoming his master. When Mika refuses to drink human blood, she allows Mika to live off of her blood, claiming that he is now her dog for eternity. For years later Mikaela and Krul have a close relationship. She enjoys his dependence on her and is the only character in the series so far who appears to enjoy being bitten. She instructs Mika to disappear during the war and find Yu after whispering her true agenda to him. Mika complies. Mika appears to trust Krul enough on taking care of Yuu. By the time Ferid and Crowley ambush both Krul and Mika before rescue Yu before the humans, once Krul gets captured by Ferid, Mika tried to save her however she tells Mika to escape. Mika hesitates about leaving Krul Behind

It unclear if Mika plans on saving Krul after rescuing Kimizuki's sister from the Humans on Sanguinem.

Ferid Bathory
Growing up in Sanguinem, Mikaela approached Ferid Bathory. In exchange for letting Ferid bite him and drink his blood, he received money and good food. Mika's true goal was to steal a map, and he succeeded in stealing both a map and a gun from Ferid Bathory. 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 Ferid fatally wounded Mika, making Krul decide to turn Mika into a vampire against his will.

Once Mika is a vampire, Mika rebels against him often, even pointing his sword at Ferid's neck in private and cutting off his arm on the battlefield, but Ferid is too strong for it to matter. Ferid wants Mika to drink human blood to stop his growth at his most beautiful age. He presented Mika to the Progenitor Council as his favorite servant and claims he cannot bear to be separated from Mika. Whenever he has the opportunity, he initiates physical contact with Mika, much to Mika's disdain. He is the only vampire aside from Krul who knows a lot about Mika, and he is using blackmail against Krul to keep her from killing him.

René Simm
Lacus and Mika's coworker. He is always seen with Lacus. He accuses Mika of stealing glory, 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 as long as Mika does his job.

Lacus Welt
Lacus is a city guard that often works with Mika and René. Mika's power impresses him, but he is concerned about Mika not drinking blood. He is chatty and often tries to start conversations with Mika, but Mika usually answers with silence. He says he does not care whether Mika lives or dies.

Aiko Aihara
Mika confronts her in Nagoya. After she orders her team to commit suicide, Mika sticks his fingers in her mouth and removes the pill she was going to use for suicide. He tries to convince her to play opossum and even lies to the other vampires, stating that she is dead. 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 Yuichiro'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 he relents and kills her without ever learning her name. He looks slightly sad for a moment afterwards. She is the first person Mika is shown to actually kill.

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

Norito Goshi
A member of the Guren Ichinose Squad. Goshi works wtih Guren and Shigure Yukimi to fight Mika in Shinjuku. He attacks with illusions. In Nagoya, he attacks Mika with a powerful illusion, but Mika charges right through it, surprising him.

Sayuri Hanayori
A member of the Guren Ichinose Squad. In Shinjuku, she 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.

Shinoa Hīragi
A sergeant of the Japanese Imperial Demon Army's Moon Demon Company. She first met Mika when they were eight years old while she was delivering messages from her sister, Mahiru Hiragi, 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. She returns the favor in Nagoya when she defends Mika from her compatriots in the Moon Demon Company and even attacks Major General Shinya Hiragi to save Mika's life, and labeled 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 is the only human besides from Yu earned his trust so far.

Shinya Hīragi
A Major General. In Shinjuku, he 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 Hiragi attacks Shinya to prevent him from killing Mika. After she defends the vampire and allows him to escape with Yuichiro, Shinya orders the army not to kill her.

Guren Ichinose
Currently the leader of the Moon Demon Company in the Japanese Imperial Demon Army. Mika is eight years old when he first meets Guren in the light novels. When Mika asks about him, Saito of the Hyakuya Sect says that Guren is a pervert. When they meet again on the battlefield eight years later, Mika 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. He wants to capture Mika as well. Crowley Eusford captures him in Nagoya.

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

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

Mito Jūjō
A member of the Guren Ichinose Squad. In Shinjuku, she 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.

Taro Kagiyama
A member of Makoto Narumi Squad. In Nagoya, he 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.

Shihō Kimizuki
One of Yu's squad members. He carries Yu on his back when Yu is unconscious in Nagoya and tries to prevent Mika from taking Yu. Mika 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.

Makoto Narumi
The sergeant and leader of his squad in the Moon Demon Company. In Nagoya, his 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 Yuichiro, 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.

Mitsuba Sangū
One of Yu's squad members. She attacks Mika when he tries to reach Mika, but he parries it. After Shinoa protects Mika and tells him to escape with Yu, she stands beside her to defend him from their own army.

Yoichi Saotome
One of Yu's squad members. He 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 Yuichiro'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 Hiragi 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.

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 puts three kunai in Mika's lateral thigh.