Tokyo Butei High School is a specialized institution where armed detectives, known as "Butei," are trained. Kinji Tooyama, a sophomore, possesses a unique physiology that triggers a "super mode" when stimulated by "something." He attempts to conceal this ability from others to maintain a peaceful existence. However, trouble finds him when he becomes a victim of a bombing incident, leading to an encounter with Aria H. Kanzaki, an elite member of the Butei High "Assault" department.