Triggered by his wife's trip back to her hometown, the husband spends time with his stepmother, Ayano, for the first time in a while. After the death of her husband, Ayano chose not to remarry, yet maintained a mature, alluring body that only grew more sensual with age. Spending long hours together awakens uncontrollable feelings within the husband. While his wife is away, the two give in to their overwhelming desires, crossing boundaries and entering into a forbidden, intimate relationship.