An introverted high school student, Souichi Sakuraba, is being bullied severely by the "Yokai" classmates. The bullying escalates, and Souichi's childhood friend, Azusa, who was the only one he trusted, was defiled by them. In front of Souichi, who was in the depths of despair, the succubus, Asmode, appeared. Souichi makes a contract with a succubus who possesses a mysterious supernatural power, and decides to make the bully's loved ones suffer the same pain as himself by "cuckolding" them. The obscene revenge by "NTR" begins.