She commands Yoichi to hide under the bed when vampires attack. Lacus Welt kills her in front of Yoichi by draining her blood entirely. Gekkouin often makes an illusion of her when he tries to take possession of Yoichi's body. Evidently his older sister cared enough to put her own safety on the line so that Yoichi could remain undetected.
Possibly Yoichi's closest friend, aside from Kimizuki. Yoichi takes every reasonable opportunity to glomp him. Yu was the one who helped him when he got bullied, and was ordered alongside him to be Yamanaka's gang's errand boys. After Yoichi reveals information about his past and his regrets of not being able to save his sister, he is hit by Yu with a soda can and tells him that Yoichi's sister wouldn't want to be avenged. In addition to this, he states that a spoiled weakling like him would have no place in the army.
However, Yoichi helps him save a civilian girl when one of the vampires from the research facilities escape. When Yoichi finds out that Yu is safe, he tearfully runs up to hug him (although he accidentally makes Yu pass out). He and Shinoa are at his bed side when Yu comes to.
The leader of Yoichi's squad. She enjoys pranking and teasing all of the members. She usually acts like she wants to protect Yoichi's innocence or blames him as the source of ideas for her pranks. From the prestigious Hiragi family. She snags herself Yoichi to deny Yu a partner he already knows in their training exercise. Later she defends Yoichi from a counter attack from Crowley.
The second-in-command of their squad. She actually has experience in battle. She is close friends with Shinoa. She gets into fights with everyone except Yoichi. From the prestigious Sangu family.
Kimizuki is skilled at cooking and often acts as the watch over his other squad members. Although he first appears to be temperamental, he actually strongly values family. When Kimizuki gets in fights with Yu, Yoichi often intervenes. Yoichi does ask why Kimizuki is being so mean when jokes about them be closer as a squad. Although Kimizuki has gotten in fights with the rest of their squad members, he has only shared barbed remarks with Yoichi and out of everyone is more laid back with Yoichi.
Guren experiments on Yoichi and makes him a bearer of the Black Demon Series. His words help Yoichi overcome his demon when he first makes a contract. Commander of the Moon Demon Company. From the prestigious Ichinose family. When Yoichi is possessed Guren orders his death as a test of resolve for the others involved. In a training exercise Yoichi is soundly defeated when he tries to ambush Guren from behind. Aside from these controlled circumstances, Yoichi is likely seen as a prized Black Demon holder.
She is Yoichi's teacher, overseeing his classes and training exercise against mannequin like contraptions. She is present on the battlefield later with Yoichi when they launch attacks on the vampires.
A member of Guren's squad. Both their squads faces off as a challenge by Guren to prove their worth and strength before the battle. Yoichi doesn't manage to fire an attack her way with his missiles dealt with by Shinya and Guren.
He coaches Yoichi on sniping when they attack Fifteenth Progenitor Lacus Welt in Nagoya. He helps calm his nerves and instructs Yoichi to snipe as many vampires as they can as the building where their vantage point is located goes down. They both together launch another joint attack on their original mark of Lucal Wesker.
Lieutenant General of the Japanese Imperial Demon Army. He tortures Yoichi and Kimizuki to force Yuichiro in telling the truth during his "interview". Though he releases them when Yu agrees to his terms, he later has no issue using them as human sacrifices for his Seraph related experiment.
Leader of his own squad. At first he believes Yoichi and his squad are undisciplined and is reluctant to work with them. He somewhat holds grudges against Shinoa's squad for the death of his comrades, but even so aids them in escaping from the battlefield at the airport and rescuing Yuichiro.
A member of Makoto Narumi's squad. She escapes with everyone else to the airport and holds a grudge against Shinoa's squad for the death of her two friends.
A member of Makoto Narumi's squad. When Yoichi helps Mika escape with Yu and other vampires attack, Iwasaki manages to escape with everyone else to the airport.
A member of Makoto Narumi's squad. She is killed by vampires when they are ambushed after Yoichi helps Mikaela escape with Yuichiro.
A member of Makoto Narumi's squad. He is killed by vampires when they are ambushed after Mikaela escapes with Yuichiro.
Kureto's personal assisstant. She is present when Yoichi and Kimizuki are tortured, and later when the survivors of the battle of Nagoya were to be used as sacrifices.
A seventeenth progenitor that they first encounter when heading back to the stronghold after their first mission. They meet once more on the battlefield of Shinjuku and are defeated. Later, they meet again at Nagoya City Hall in attempts to rescue trapped soldiers.
A thirteenth progenitor that they first encounter when heading back to the stronghold after their first mission. For a short while they engage in combat with him. Yoichi tells him to eat his cursed gear weapon attack, though has to rely on his squad members covering him when Crowley counterstrikes. They meet once more on the battlefield of Shinjuku and are defeated. Later, they meet again at Nagoya City Hall where Crowley rules over in attempts to rescue trapped soldiers. Yoichi is the first to spot him through the window and requests confirmation that he can attack the noble whilst he can. He later attacks again to cover their retreat at this foe that they are unable to overcome.
A servant of Lucal Wesker. He is sacrificed as a meat shield when Yoichi fires at Lucal to kill him. Yoichi's arrow strike is part of a joint attack that destroys Esther instantly, leaving just his arm behind.
A seventeenth progenitor that they first encounter when heading back to the stronghold after their first mission. They meet once more on the battlefield of Shinjuku and are defeated. Later, they meet again at Nagoya City Hall in attempts to rescue trapped soldiers and Yoichi fires spectral arrows at her to give them a chance to escape.
The vampire who killed Yoichi's elder sister. Since he was under the bed when the incident occurred, Yoichi does not appear to recognise him when they meet on the battle field years later.
Yuichiro's family, who was forcibly transformed into a vampire. Yu convinces Yoichi to help him save Mika later on. When they are running to Nagoya airport, Mika fights his way through the entire regiment to retrieve Yu. Yoichi grabs Mika from behind to prevent him from leaving with Yu. He clutches him and appeals to Mika that they are the same family. Though he is swung off by an aggrieved Mika, who raises a sword to him, Yoichi is shocked when Mika is stabbed in the back by a rifle bayonet.
Yoichi's demon. He often replays memories of when Yoichi's sister died at Lacus's fangs. Although he possesses Yoichi at first, they come to get along. They chat when Yoichi goes to sleep, even going so far as to discuss their favorite colors. Thanks to this, Yoichi masters manifestation without any help.
A bully at Second Shibuya High School who pushes over and mistreats Yoichi. He complies with Satoshi's demands that he buy them stuff as Satoshi assures him that they are friends and he has been admitted into the Moon Demon Company.
A bully at Second Shibuya High School who joins in picking on Yoichi. He runs from him thinking he has returned to bully him, then agrees to help him after hearing otherwise.
A bully at Second Shibuya High School. Despite the bad way Yoichi was treated by him, he still helps rescue Yuuji when he is possessed and overcome by a cursed gear weapon.