Հիմնաբառը Japanese Middle School Students

The story begins with Keita Suminoe, a male third-year junior-high school student studying for his high school entrance exams. He is living in a home with his older twin stepsisters, Ako and Riko, who share no blood relation to him, and they help him prepare for his exams. Even though he initially dislikes himself for it, he begins to become attracted to his two step-sisters, and his two parents encourage him to eventually get married to one of them.

Three teenagers attempt to commit suicide and fail. When they wake up in the hospital, they learn they have acquired mysterious superpowers. These abilities are usually passed down through generations of heroes, and are something that only allies of justice can possess… But the directionless trio, who feel there is no place for them in this world, choose to use these powers for evil in order to destroy the world.