A selfish vampire in her early teens, Hazuki was restrained in a castle in Germany since she was separated from her mother. She escapes the castle with Kouhei's help and flees to Japan in search for her mother. Curiously when a vampire drinks a mortal's blood, this human becomes his/her servant, but for some reason Kouhei was unaffected when Hazuki did it to him. Despite how she claims he must serve her as a slave and obey every command of hers, Kouhei refuses to do so. Her family is desperate to retrieve her because according to them, she is a "daywalker", a vampire who, unlike others of her kind, can withstand sunlight. She is plagued by an alternate personality named Luna that is forced upon her by her vampire relatives to keep her under control.