Ayumu Aikawa is a normal high school boy. One day he is killed by a serial killer and revived as a zombie by a necromancer named Eucliwood Hellscythe. He starts to serve Eu as her guard but he happens to deprive a magical girl in a pretty pink dress of her powers. After which she orders Ayumu to fight against the "Megalo" demons in her place.

Ayumu Aikawa must continue to fight the Megalo in place of Haruna, who continues to recharge her magical powers. While trying to figure out the mysteries behind the people who are releasing these Megalo in the world, Ayumu meets a beautiful, black-haired girl by chance, and she only has eyes... for his butt.