The warden of that prison… is a yakuza.

In a world where prisons have been privatized, yakuza boss Kizaki (Riki Takeuchi) runs Gokukaijima Prison and has taken the position of its warden, the inmates are all women, Mari (Yuri Morishita), who has just been incarcerated, is defiant, She refuses to submit even to the violence of the guards, In truth, Mari committed her crime deliberately in order to get close to Kizaki, Meanwhile, a mysterious group harboring a grudge against Kizaki is planning an assault on Gokukaijima Prison.