Ruka (Yuma Nakayama) is a young vampire, but hasn't yet to mature into a full-fledged vampire. His cannies have yet to fully develop, which means he still hasn't tasted human blood or, at least, human blood that he's drawn himself. In order to get him prepared, he is cast down into the world of humans, where he boards with Jiro (Shiro Ito), the owner of a Chineses restaurant, and enrolls in high school. His homeroom teacher Makoto (Rosa Kato) is a cheerful, though meddlesome, young woman who catches the fledgling bloodsucker off-guard. Is he actually falling in love with a mortal?