The story centres around a passive high school boy named Aikawa Ayumu, who gets killed during a spate of mysterious serial killings. However, Ayumu is resurrected as a zombie by the necromancer girl Eu, whom he had befriended just before dying.
When Ayumu reawakens he is tossed into a world with masou shoujo (magically equipped girls) and vampire ninjas. And of all things, he is assigned the duties of such a masou shoujo by the magical warrior girl Haruna.