Mana Sakura, a newly appointed female teacher, was gang-raped in STAR-511.

Mana Sakura becomes a teacher to fulfill her mother's wish. Gentle as she is, she secretly works at a bar to support her ailing mother. One day, while preparing for class, a note slips through the pages of her textbook… From that moment on, Sakura's life as a teacher becomes one of humiliation and shame, as she is gang-raped by her students…