Staz is the vampire boss of a section of the demon world, but he has little interest in human blood. He's more infatuated with Japanese culture. When he learns that Yanagi Fuyumi, a Japanese teenage girl, accidentally wanders into the demon city, he jumps to the occasion. However, while Staz deals with an intruder on his turf, the oblivious Fuyumi is killed by a monster and becomes a wandering ghost. The disappointed Staz vows to her that he will find a way to bring Fuyumi back to life.
— Description from AniList community (anilist.co).
