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. After being framed for starting a fight, she is taken away and tied up. Can the shy Himeno ever escape this living hell?