Ayumu Aikawa, a slacker student, is the focus of the narrative and is murdered off during a string of unsolved homicides. However, a girl named Yuu, who Ayumu met just before he passed away, helps him come back to life as a zombie. Ayumu awakens in the world of Maso Shoujo, which features vampire ninjas and heroines with supernatural talents. Ayumu is now entrusted to the magical warrior girl Haruna and given the responsibilities of such a girl.