Mari begins working as a housekeeper to pay off her late husband's debts and support her son Shuji through college. Driven by financial need, she is seduced by her drunken employer Shigeru, who manipulates her body at his whim. Her son Shuji accidentally witnesses the act, and soon he too begins to lure Mari, setting off a disturbing game. As payment, she is forced to urinate in the yard, tied up like a scarecrow, made to suck cock, and spanked on the ass with a wet rag in increasingly extreme situations. When Shuji's older brother Kazuaki joins in, the game escalates into full-blown slave training, driving Mari deeper into submission.