Mayumi is sent to jail after brutally attacking her partner and his mistress. Sent to live in Cell 31, the women there couldn't be more different... they are very religious, sing hymns and discuss the Bible. A fight with a rival cell block starts a bloody and vicious war in the jail... one where the warden and guards seek vengeance on the women with brutal torture and sexual humiliation. When a new inmate arrives and Mayumi recognizes her, all hell breaks loose!

"Jealous" man-killer Mayumi (Hitomi Kozue) is sent back into solitary confinement after being re-arrested for the murder of the doctor who fingered her for a botched surgery. After emerging from solitary confinement to find an all-new gang of bullies picking on a meek, young female prisoner, Mayumi is now a much harder soul who takes no attitude from anyone, and she turns savage when the poor girl is enslaved by Yakuza.

A nurse is framed for medical malpractice. In prison she meets the boss of their cell who is in for a crime of passion. They both have a reason to escape... revenge.