Natsumi (Ai Takeuchi) is compelled to work in a steel factory to settle a debt, a place known for employing women with troubled histories under exploitative conditions. She's assigned to a team of four women led by Atsuko (Nagisa Umeno) by Chief of Security Tsukada. When one of the workers disobeys orders, Tsukada rapes her, and Natsumi becomes his next target. As Natsumi struggles against the factory’s oppressive atmosphere, she faces obstacles from managing director Hideko and president Kamiyama. Ultimately, Natsumi must confront the factory's corruption.