What is the only thing these three deaths have in common: a groom that hangs himself at his own wedding reception, a seventy-year old man who throws hijmself through a plate glass window and a teenage track star who runs herself to death? Before ending their lives all three mentioned 'The Green Monkey'. Baffled by his only clue, Detective Sakurai consults the young psychologist, Saga Toshiya, who believes that hypnosis might be responsible for the shocking deaths. His belief is strengthened when the troubled Yuka appears on a popular television show and mentions "The Green Monkey" under hypnosis. The sinister TV hypnotist Jissoji who uses his powers to attain his own ends becomes the prime suspect. But is he the creator of "The Green Monkey" or are even darker forces at work?