A secret agent is dispatched to a music academy located on a remote island, where the faculty has been subjecting students to sadistic torments and selling them into the sex trade. This institution, the Sparta Academy, is a prestigious prep school where students who break even minor rules face brutal, humiliating punishments in a special torture chamber. The kind-hearted student Mayumi and her classmates become the latest victims of the corrupt, perverted instructors.

When the undercover agent proves unable to stop the abuse, the legendary heroine Kekko Kamen arrives to fight for justice. Wearing only a red mask, red boots, and red gloves, she wields nunchaku and uses her body as a weapon, often defeating her enemies by stunning them with her exposed private parts. During her appearances, Kekko Kamen performs a rock n roll version of her own theme song while battling the faculty.

The academy is run by a bald headmaster with a metal claw who treats students like instruments, aided by a Mozart-obsessed assistant who punishes gum chewing and can flatulate the melody of Beethoven's Fifth Symphony. The faculty also includes masked teachers and hall monitors who enforce a curriculum of depravity, with special detention sessions held beneath the gymnasium. As Kekko Kamen confronts each twisted instructor, she gradually dismantles their operation and rescues the students from the remote island academy.