When Kōichi Sasakibara transfers to his new school, he can sense something frightening in the atmosphere of his new class, a secret none of them will talk about. At the center is the beautiful girl Mei Misaki. Kōichi is immediately drawn to her mysterious aura, but then he begins to realize that no one else in the class is aware of her presence.
Senō Natsuru is your normal, everyday high school student. However, he's been chosen to be a Kämpfer, who's objective consists on fighting other Kämpfer with either guns, swords or magic. However, there's catch—first, you can't chose if you're a Kämpfer or not, and second, you must have the body of a girl to use your powers.