Ai, a high school girl, begins working part-time in violation of school rules to earn tuition after her father loses his job. One day, her classmates discover her secret and she is threatened by upperclassmen: "If you don't want to be expelled, do exactly as we say." Trapped in a desperate situation, Ai must submit to their cruel demands. A tense, harrowing story unfolds as she endures repeated gang rape, humiliation, and confinement at the hands of her tormentors.