Reiko, the stepmother, suffers through unsatisfying nights with her husband, leaving her desires unfulfilled. Though technically her stepson, they share no blood relation. Yet, in the presence of a younger man, uncontrollable urges begin to stir, driving her sexual appetite into overdrive. Losing all sense of morality, Reiko even seduces her son's friends, unafraid to cross the line into incest. Constantly craving her stepson's cock, she is consumed by an insatiable, relentless impulse to satisfy her lust.