Koishite Akuma (2009)

Ruka has yet to mature into a full-fledged vampire. His canines 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, the owner of a Chinese restaurant, and enrolls in high school. His homeroom teacher is a cheerful, though meddlesome, young woman who catches the fledgling bloodsucker off-guard. Is he actually falling in love with a mortal?