A violent teen and three others kidnap a young nurse while escaping from a Texas mental institution. Pursued by a vengeful sheriff, the disturbed young man embarks on a murderous rampage that shapes him into a legendary killer known as Leather face.

Dr. Hattori and her husband watch footage of brain surgery experiments with Manchurian, Russian and Japanese guinea pigs that had been found in the basement of a wrecked hospital. Out of the blue, there is a white light and when they look back, they see they children Ota Miyuki and Kaori staring at the light. Years later, Miyuki vanishes from the Tama Medical University Hospital and her sister Kaori, Miyuki's boyfriend Motojima and detective Hirasawa are seeking her. However, Miyuki and the teenagers Kazochi, Takumi, Hattori and Rieko have been submitted to a nightmarish experiment by Dr. Hattori and her team with tragic results.