Jitsuroku onna kanbetsusho: Sei-jigoku (1975)

A group of beautiful young girls winds up in a juvenile hall because of their constantly getting in trouble with the law. The facility turns out to be a horrible place, where inmates are subject to constant beatings, sexual assaults and various forms of abuse. One inmate decides she's had enough and fights back, all the while developing an escape plan to take revenge on the person who had her thrown in jail in the first place.