I have crossed a line

Japanese women in prison film from 1987. Shinobu Himeno is arrested and thrown into Asahi Female Prison for being an unwilling accomplice in a jewelry store robbery. She’s to serve her sentence in the infamous Cell Block 21, a dismal area full of tough, sex-starved women. Himeno is bullied and abused by inmates and guards and, after being framed for starting a fight, is taken away and tied up by the prison’s infamous Mr. Kiya. Through flashbacks, we discover why many of the women have been locked up here and soon, in one great act of defiance, they rise up to overtake the prison in a bloody, violent riot! Can the shy Himeno ever escape this living hell?