Natsumi (Ai Takeuchi) is forced to work in a steel factory in order to pay off a debt, a factory notorious for employing women with "dark pasts" as slave labor. Tsukada, Chief of Security places Natsumi in a team of four women led by Atsuko(Nagisa Umeno). When one worker fails to follow instructions, Tsukada rapes her, and Natsumi is next on his list. Natsumi tries to fight the insanity, but is hindered by managing director Hideko and factory president Kamiyama. It is up to Natsumi to take on the evildoings of the factory.

After Azusa witnesses a rape at her previous job, she takes a job at a steel factory in a desolate part of town. Her co-workers hate her and her only friend is a young girl, Naomi. A security guard sexually abuses Azusa and Naomi disappears under mysterious circumstances. While the mystery surrounding Naomi’s disappearance deepens, Azusa finds a clue and the stage is set for a climactic showdown at the factory.