A nerdy young college instructor named Shinji Kikyo returns home one day to find himself the target of a mad assassin. Surviving somewhat miraculously, he fends off other assassins and, with the help of the reporter Keiko Tsurumaki and the car mechanicBill Otomo, eventually discovers that a "population control" association is really an assassination squad led by Shogo Mizorogi, who has been training patients in a mental asylum to become killers. Along the way, it starts to appear that Shinji may not be the mild-mannered academic he seemed at first, but a well-trained secret agent.