After a bizarre transformation into a girl, Natsuru learns he's a Kampfer – a mystical fighter battling others of his kind in female guise. Amidst romantic complications with a childhood friend now enamored with his feminine form, Natsuru faces the added challenge of attending both the boys' and girls' sections of his school. Gossips swirl about Natsuru dating himself, while rival Kampfers, armed with swords and guns, pose a deadly threat. In this whirlwind of hormones, combat, and confusion, Natsuru must embrace his new role as a gender-blending defender or risk a grim fate.