Nao, the stepmother, finds her son Kenta in trouble at school and visits his homeroom teacher to discuss the matter, only to be pressured into taking the blame herself. To prevent Kenta's expulsion, she is forced to agree to "bodily service" as a condition. Yielding to the teacher's intense demands, Nao submits to the act—unaware that her son's friend, Kojima, has secretly witnessed everything. Kojima smirks and taunts her, saying, "I wonder what you and the teacher were doing, Auntie... Should I tell Kenta and your husband everything? (laughs)" Having remarried with a child from a previous relationship, Nao's life took an unexpected turn—and now, caught in this compromising situation, she begins a new life as a pleasure-driven, obedient sex slave.