Hitomi is caught masturbating by her perverted stepson and blackmailed. To deepen her humiliation, he uses his authority as a son to involve her daughter in an intense SM session. The mother is forced to administer enemas, while the daughter is made to defecate. Taboo acts beyond familial boundaries unfold as the mother and daughter lose all reason, craving each other's bodies. Their desire escalates endlessly, driving them toward the ultimate act of incest.