Yoshio Mita is a student of Syuten Academy but in fact he is an undercover agent to investigate the academy’s dark side. However， discipline committee takes Yoshio’s roommate Fumio Takagi in on human experiment. Yoshio is given Sexy Mask’s costume by Makiko Misora, a student council president, and decides to fight to rescue Takagi. Sexy Mask brings peace to the academy but the president of the school Syusaku Nameoka is suspicious of an only female student Makiko Tomisora. Syusaku tries to beat up Makiko as a warning to other people. Then, Sexy Mask appears to remove the suspicion of Makiko. However, other students are excited with Sexy Mask’s naked body and lose their senses. They start licking Sexy Mask’s body.