Yuu, a married woman, was happy that her son had made a serious, well-behaved friend named Yoshino. However, Yoshino's true intention was to target Yuu's voluptuous and alluring body. Taking advantage of the times when her son was away, Yoshino pounced on her. Though Yuu tried to endure it for her son's sake, contact with the young man's body unintentionally awakened her own suppressed desires. Realizing this, Yoshino's actions grew increasingly reckless, deepening their forbidden relationship.