Tsukushi, a student, has been married since birth to a man whom his parents have chosen for him. On the fateful day of their first meeting, a man called 'Oni', the student council president of the school he attends, appears! Tsukushi is shocked, but agrees to live with Higashima on the condition that if he doesn't change his mind by the time he graduates, the marriage will be annulled...! Includes a chapter on Higashima's childhood friends, Ichiryu and Yuto, at the same time! A high-tension love comedy!