Japan. A young man studies in high school. He is older than he seems, because he is a vampire... He drank the blood of already doomed boys or girls, but he did not disdain animal blood either. Little blood is needed to survive. But in order not to be identified, he had to change his form, inhabiting first one, then another. When he lived to the death of his body, he inhabited another. Now he is Kobayashi Roka. Roca, 17, plays several sports. In past lives, he studied a bunch of different martial arts, so his body was prepared for all sorts of incidents, and regeneration even allowed him to lose some parts of his body. But growing them took a lot of time, although the fractures healed quickly, you just had to drink more blood when nothing happened; blood, practically speaking, was not needed, only for growth.