Single mother and busty housewife Sawaki Erika struggles with an intimate dilemma—her beloved son cannot wean himself from touching her breasts. As her voluptuous breasts are repeatedly groped by her growing son, she panics and protests, "No, stop it..." yet he never listens. One day, her son catches her masturbating to relieve her heated desires. After that incident, she finds herself frequently assaulted from behind, her breasts fondled by him even during daily chores. Torn between her pride as a mother and her son's uncontrollable lust, how will she confront this forbidden relationship?