He is the next leader of the JIDA. In the novels Kureto often reminds Shinya that he is his superior and he should not double cross Hīragi family. He suspects Shinya may be a vampire spy because he is close to Guren. He says he trusts Guren and sends Guren on an extremely dangerous mission to Nagoya. A member of the prestigious Hiragi family.
Guren's lover and Shinya's former fiancée. He agrees to pretend to be her fiancee after she reveals she is in love with Guren. Their time together made Shinya develop genuine romantic feelings for her but they remained as unreturned as always and eventually Shinya lost any desire to win her over but still showed jealousy when he learned Guren and Mahiru had sex. In their final meeting, Shinya taunted Mahiru on her obsession for Guren, which proved to be a fatal mistake, angering Mahiru greatly, causing Shinya to die very painfully, much more so than the rest of Guren Squad. Due to being aware of Mahiru being the demon in Guren's sword, Shinya is wary of the possibility of Mahiru taking over Guren and when his fears did happen, he desperately tried to return Guren back to his normal self.
A higher-ranking member of the JIDA. A member of the prestigious Hiragi family.
Shinya meets Shinoa when he is sixteen and is friendly towards her due to her relation to Mahiru. A squad leader in the Moon Demon Company. Guren uses Shinya and Mito Jujo to help train her briefly before the attack on Nagoya. Shinya works with her and Narumi's squads in Nagoya. Although Shinya spectates her betrayal for allowing Mikaela to escape, it can later be seen that he still places his trust in her.
Leader of the Japanese Imperial Demon Army as well as the Hiragi family, he adopted Shinya into the Hiragi family as a fiancé for Mahiru. They do not have a good relationship.
A member of Guren's squad since he was 16 back in high school prior to the apocalypse. He enjoys making fun of Guren, and Shinya and he often team up to do so. A member of the prestigious Goshi family. Shinya and Norito appear to good friends and often team up to annoy Guren.
A member of Guren's squad since she was 16 back in high school prior to the apocalypse.
A newbie soldier, who Guren experimented on. A wielder of a Black Demon. A member of Shinoa's squad, and a hothead, who challenged Shinya to a fight. He knows little about the Hyakuya Sect. When Yūichiro tried to make his attempts in rescuing Guren from Crowley and his aides, Shinya commanded that they retreat under Guren's final command.
Commander of the Moon Demon Company. Shinya and Guren have been friends since high school and his first friend. Guren loved Mahiru Hiragi, Shinya's fiancée. When he learns Kureto gave Guren a suicidal mission in Nagoya, Shinya joins with Guren to help him. Shinya enjoys teasing Guren. Both Guren and Shinya made the main attacks on Crowley and after several attempts of trying to attack. In their attempts to retreat, Crowley still manages to catch up to them in a playful manner. Upon being captured by Crowley, Guren placed Shinya in charge and gave his final command that he and the other troops head to the rendezvous point at the airport. When Shinya meets a possessed Guren, he is infuriated by how Guren remorselessly kills their friends and is not at all moved by Guren's ruthless justification of it being necessary for what they dreamed of. However, he still furiously tries to get him back into his senses, to no avail. He then realizes that Guren has been possessed by Mahiru. Three months later, an imprisoned Shinya receives news from Aoi that Guren and Kureto will be returning sooner. He is also informed that Guren wishes to speak to him upon his return. Later it is revealed by Ferid that Guren revived his whole squad, including Shinya. After Guren confronts him in cell, Shinya says he no longer will be able to forgive Guren. Shinya was the first to be resurrected using the forbidden taboo Seraph of the End showing just how Guren cares for Shinya. Having been with Guren for a long time, Shinya still doesn't understand his reasoning for becoming a Namanari and saving the world even after he tried to stop his actions to no avail.
A member of Guren's squad since she was 15 back in high school prior to the apocalypse. She appears to be tsundere toward Guren, but he is not interested. A member of the prestigious Jujo family.
Kimizuki's little sister and possesses the Seraphim of the fifth trumpet. Shinya witnesses her bring forth the demon Abbadon and wrecks the airport's landscape. In the end she is defeated by Yūichirō as the King of Salt with the second trumpet.
A newbie soldier Guren experimented on. A wielder of a Black Demon. A member of Shinoa's squad. He gets tricked when Shinya attacks them from behind during a match to train Shinoa.
Leader of his own squad, he refuses orders from Shinya and makes the decision to abandon the mission and head back to rescue Guren, of which Shinya comes to agree with.
The personal assistant to his older brother Kureto. She controls the chains that are used to absorb the blood of both vampires and humans alike for the Seraph. Shinya addressed her as Kureto's pet dog and questions her about her sister.
A soldier of the Moon Demon Company. She works under Shinoa as part of her squad. A member of the prestigious Sangu family.
A newbie soldier Guren experimented on. A wielder of a Black Demon. A member of Shinoa's squad. He gets tricked when Shinya attacks them from behind during a match to train Shinoa. Shinya coaches him on sniping. Both of them take on the sniping tasks during the Nagoya war.
A member of Guren's squad since she was 16 back in high school prior to the apocalypse. She does not speak often.
An extremely powerful vampire, who gets Guren by the neck during the battle at Shinjuku. Until Shinya snipes him, that is. Fortunately, he escapes the battle with minor injuries. In the light novels he helps Guren to revive Shinya.
A seventeenth Progenitor and noble serving under Ferid's faction. Their encounter is on the battlefield in Shinjuku, then later again at Nagoya. She along with Horn and Crowley chases after Shinya as he tries to escape with Guren.
A powerful vampire that fights at Ferid's side. In Nagoya after capturing Guren, Shinya appears to rescue him. He chases after them in an almost playful manner. Due to his outrageous power, Guren ordered Shinya to take command to lead the rest of the troops to the airport.
He stabs Mikaela when he runs towards them, but can later seen that the two as well as Shinoa's Squad aid each other in escape.
A servant to Lucal Wesker. He is sacrificed as a meat shield after Yoichi snipes at him with Shinya by his side.
A seventeenth Progenitor and noble serving under Ferid's faction. Their encounter is on the battlefield in Shinjuku, then later again at Nagoya. She along with Chess and Crowley chases after Shinya as he tries to escape with Guren.
Shinya works with Shinoa and Narumi's squads to exterminate him in Nagoya. Along with Yoichi they make the first move on Lucal by launching sniper attacks. However, these were blocked by Lucal as he tossed Esther Lee to take the shots. After going down on the tower Lucal slices though, Shinya makes his way closer to cover his fellow squad members and fires at close range to help defeat Lucal.
Byakkomaru is the demon Shinya formed a contract with and became his Cursed Gear after Shinya went through an underwent operation to increase his chances of handling a Black Demon Series and emerged from the operation successfully and ever since he became his primary weapon. He is very protective of Shinya as he threatens Mahiru Hīragi if she should ever harm Shinya.