|Anime Debut||Episode 2|
|Voice Actor||J. Michael Tatum|
- "You see...I wanted to become a victimizer."
- ―Seishirou to Natsuno
HistoryHe was born to two wealthy parents who had both a high social status and wealth, but he felt its members were "nothing but scum." His father was prone to domestic violence and his mother was extremely haughty. Chizuru killed them and showed Seishirou a whole different world. Since neither of his parents rose, there was zero chance that he would. He begged Chizuru to take everything that he inherited from his parents and let him stay with her in exchange. He was finally happy. Sometimes, they drank his blood, but he embraced such occasions with joy.
On August 11, he, along with Tatsumi welcome Megumi before she goes missing.
At 11 o'clock at the Ozaki Clinic, he hears a gunshot. Seishirou Kirishiki shot the projector that projected that crisscross patterns. Seishirou, holding a gun, tells him not to move. Chizuru Kirishiki is also with him.
Seishirou tells Toshio to raise his hands. He knows that he can't do anything to a human with a gun and instead runs to the phone.
As Toshio and Chizuru went through the festival, Atsushi Ookawa and Seishirou Kirishiki watched from a distance.
As Toshio happily smiles to himself as the other villagers discover that Cizuru had no pulse and is cold to the touch, he hears Atsushi Ookawa and Seishirou Kirishiki drive up in their car. Atsushi yells to let go of her and drives the car into the crowd. Tomio stops the car with his hands and the villagers realize that he's come back to life as well. Atsushi turns the car around as he realizes that he can't beat his father.
- "Chizuru was the one to rid me of that trash."
Seishirou has been shown to be extremely bitter towards his parents. He described them as trash and said that he felt like he wasn't alive while living with them.
Chizuru and Seishirou seemed to have met after she murdered his parents. Seishirou was greatful for this and felt that she showed him "a whole new world." As both of them passed with out rising, there was no chance that he could rise either. Instead, he begged Chizuru to take everything he inherited from his parents and let him stay in exchange. Though they are just posing as a married couple, Seishirou truly loved her and becomes jealous whenever she "cheats" on him.
Sunako's adoptive father.He's the only human in the Kirishiki househould. His job is taking care of the properties. Seishirou originally came from a distinguished family, but he found his parents vile and disgusting. Chizuru killed them both, but refused when Seishirou asked her to turn him into a vampire too, pointing out that since his parents didn't rise, he probably couldn't either. Since then, Seishirou has been with the Kirishiki family and thinks of them as his own, and occasionally gives blood to Chizuru.
Battle Against ShikisWhen Chizuru is killed by the village doctor Ozaki Toshio, Seishirou attempts to get revenge by shooting Ozaki. He ends up shooting and is attacked by Natsuno before he can shoot Ozaki. Natsuno ends up biting Seishirou and then orders him to attack his vampire family.
AnimeIn the second-to-last episode of the anime, he encounters Yoshie who he then, under Natsuno's orders, shoots her in the head. The shot was fatal and instantly killed her. Later, In the last episode, he is shown inside the burning village, standing before the Kirishiki mansion, which was now in flames. He smiles and willingly walks into the castle where he dies in the fire.