A world where demons and humans fight - the Demon King is said to be the most terrifying in this world. The hero entered the Demon King's castle alone. "Why have you incited the demons to various villages and caused harm to the people?" the hero asked. ...But the Demon King knew nothing. Really. It was something the other demons did on their own, and the Demon King did not order them to do. But the Demon King's pride did not allow him to tell the truth. "Does a superior species need a reason to trample on an inferior species?" "...Then I can do it, right?" At that moment, the Demon King was immobilized by the hero's magic. And then she was taken to a bed...? She was kissed, her breasts and private parts were exposed, and she couldn't resist the pleasure she had never felt before... The Demon King, who had reigned with overwhelming power, was now dominated by the Hero... "I won't kill you. You're mine." What is the Hero's true purpose?