In a Japan overrun with people possessing supernatural abilities, Shura Yagami, a cleaner, cracks down on the monsters who misuse their powers. He is able to defeat these monsters because he possesses the "Kyōjin Kekkai" gene, which boasts unparalleled strength and allows him to exhibit combat abilities said to appear only once every 100 years. The national government, noticing this, begins sending girls with supernatural abilities as candidates to become Shura's bride in order to secure another powerful gene.