The S-class exorcist who punched the Black Mountain old monster and kicked the werewolf leader was turned into a blood servant by the vampire princess and was captured at the Monster Bride Academy. He wants to teach the eldest lady of the monster family and his fiancée exorcism. He is the only man on the island and is asked by the vampire princess to open a harem on the island! No! As an exorcist, having a harem of monsters is too dangerous and he must escape.