Teacher Yuri finds herself trapped after trying to protect a student from a gang of delinquents. Bound in a classroom late at night, she is gang-raped and filmed, leaving her at their mercy as their sex slave. During class, she's forced into secret humiliations, and after school, she's used against her will in front of numerous students. She is further degraded by being forced to have sex with a bullied student, enduring escalating shame and terror.