Family
Mirai Kimizuki
Kimizuki Shihō's younger sister and whom he loves deeply, Shihō has taken care of her since she became afflicted by the Apocalypse Virus in 2012; however, caring for Mirai was very hard for Kimizuki, as he had to carry her, due to the Virus inhibiting her ability to move on her own, to avoid both the Horsemen of John and the vampires. Even when Mirai told his friends she wanted to die and they tried to get Shiho to kill her, he refused. In 2020, he becomes a member of the Japanese Imperial Demon Army's Moon Demon Company in order to pay for her medical expenses and get proper care for her. He later states he would betray Shinoa Squad if it would let him rescue his sister.
Japanese Imperial Demon Army
Yayoi Endō
A member of Makoto Narumi's squad. She is killed by vampires after Mikaela escapes with Yuichiro.
Shinoa Hīragi
Shinoa was Shiho's supervisor prior to supervising Yuichiro. She tries to get the two to get along.
Shinya Hīragi
Major General of the Japanese Imperial Demon Army. He is present when he along with Yoichi are tortured to force Yuichiro into answering honestly in his "interview".
Yūichirō Hyakuya
He and Yuichiro had an uneasy relationship. They do not get along and would often fight each other.
Guren Ichinose
Like Yuichiro, Guren initially did not allow Shiho to join the Moon Demon Squad because he was still not ready to control a demon, warning him of the consequences.
Rika Inoue
A member of Makoto Narumi's squad. She holds grudges against the Shinoa squad for interfering and allowing Mikaela to escape with Yuichiro, resulting in two of her friend's death.
Shūsaku Iwasaki
A member of Makoto Narumi's squad. He escapes with everyone else to the airport but soon afterwards is killed by Kureto.
Mito Jujo
A member of Guren's squad. Both their squads faces off as a challenge by Guren to prove their worth and strength before the batle.
Taro Kagiyama
A member of Makoto Narumi's squad. He is killed by vampires when they are ambushed after Mikaela escapes with Yuichiro.
Makoto Narumi
Leader of his own squad. He holds some grudges against the Shinoa squad for his friends' death, but just the same works alongside them to defeat vampires and humans alike when the Seraph is activated.
Mitsuba Sangu
It would seem both Kimizuki and Mitsuba get along with each other, but this does not prevent Kimizuki from scolding Mitsuba whenever she screws up. Kimizuki and Mitsuba tend to beat up Yuichiro when he does something stupid.
Yoichi Saotome
They get along well with each other, although Kimizuki is still concerned of Yoichi's membership in the JIDA as much as Yu does.
Vampires
Chess Belle
A seventeeth Progenitor that they encounter when they first head back to the stronghold after their first mission. They meet again on the battlefield of Shinjuku and are defeated by the vampires.
Crowley Eusford
A thirteenth Progenitor that they encounter when they first head back to the stronghold after their first mission and engages in short combat with. Kimizuki runs into him with the vehicle they are driving right after they jump out. They meet again on the battlefield of Shinjuku and are defeated by the vampires.
Mikaela Hyakuya
Childhood friend and family member of Yuichiro. He does not have any personal trust with Mikaela, but he allows him to escape with Yuichiro while defending them with the rest of the squad.
Esther Lee
A servant of Lucal Wesker. He is sacrificed as a meat shield when they attack the noble vampire as their assigned mission.
Horn Skuld
A seventeeth Progenitor that they encounter when they first head back to the stronghold after their first mission. They meet again on the battlefield of Shinjuku and are defeated by the vampires. She drinks Kimizuki's blood when she defeats him.
Lucal Wesker
A fifteenth Progenitor they are assigned to kill. With the cooperation of Makoto's squad, they successfully get rid of the vampire noble.
Demons
Kiseki-o
Kiseki-o serves as Kimizuki's cursed gear and takes the form of twin swords. He asserts his dominance over Kiseki-o through violence, something Yu and Yoichi do not do. He often torments Kimizuki with visions of his sister.