One day, Yume, a gentle older sister who cares about her younger brother, finds out that her younger brother is being bullied at school. Wanting to help her brother, she disguised herself as a man and broke into her brother's school for boys. She tries to stop bullying by grasping the weakness of the main culprit of bullying, but on the contrary she finds out her biggest weakness. That means Yume is a woman. She is immediately preyed upon by savage men and nightmarish days of gang rape begin.
