Natsumi had been divorced from her husband for nearly a dozen years. Her son, Shou, constantly worried about his mother, who showed no interest in remarrying. However, when Shou reached his third year of ● school, a man named Kitano began frequently visiting their home, and Natsumi's behavior started to change day by day. Concerned, Shou one day peeked into the room where Kitano and Natsumi were together—only to be met with a shocking sight. There was Natsumi, taking Kitano's throbbing cock, her tight, hot anus fully accommodating his thick shaft. The sound of her moans shook Shou to his core, and her expression of agonized pleasure left a deep scar in his heart. The story unfolds with intense focus on how the relationship between mother and son will transform from this moment on.