Masaya (Kenshi Okada) wiles away his gloomy and far from ideal university days. One day, he receives a letter from the worst serial killer in history Haimura Yamato (Sadawo Abe), who has been convicted of nine murders and sentenced to death. In the letter, Haimura admits to eight murders but insists the last was not committed by him. Accepting Haimura’s request to find the true killer, Masaya begins to investigate the last of the murders. As he dives deep into the criminal mind, a shocking truth is revealed which proves to be nauseating.