This movie takes place at the "School of Hope", apparently a school for overly mature and improbably attractive delinquent Japanese high school girls. In the the opening scene a girl is being tortured by a group of her fellow students called the "disciplinary committee". They have her hooked up to a machine that is slowly draining the blood from her body (for some reason, this requires her to be topless). The victim escapes but dies from falling off a building. The action then shifts to three girls who have just been committed to the school. They team up to help one of them, "Noriko the Cross" (Miki Sugimoto) take revenge on the "disciplinary committee". But then to complicate matters a rival gangleader (Reiko Ikke) also shows up to challenge "Noriko" (she rides her motorcycle right into the school, which you would think would get HER thrown into reform school, but apparently not in Japan). Eventually though the girls all realize who their REAL enemies are and team up against the corrupt male lechers running the school.
This "pinky violence" film has all the hallmarks of the genre--lesbianism, gratuitous shower scenes, girl-on-girl torture and violence. The sex and nudity is always appreciated, but the torture scenes are pretty unpleasant (albeit imaginative). Fortunately, the violence is not as graphic as it could be. The treatment of the male characters is pretty cynical--they're almost all lecherous perverts with "uniform" fetishes except for the vice principal, who's just plain evil. and a mercenary tabloid journalist who is the only male protagonist. Miki Sugimoto would go to appear in "Zero Woman--Red Handcuffs" and Reiko Ikke would go on to appear in "Sex and Fury", both of which would have a big influence years later on Quentin Tarantino's "Kill Bill". Both are pretty appealing (if not particularly believable as teenage delinquents).
This is a actually pretty big-budget and well-made film (according to genre expert Jaspar Sharp the "pinky violence" series differs from other Japanese "pink" sex films in that they were made by a big studio and had much bigger production values). These kind of films obviously aren't everybody's cup of sake, but if you like them in general, you'll probably enjoy this one.