Ever since childhood, Jun has been overly attached to his mother, Shoko. As the years passed, his affection grew twisted, and Shoko gradually found herself drawn into his overwhelming emotions. One day, a memorial service for his sister-in-law's family takes place, and with her husband too busy to attend, Shoko travels to stay overnight at her relatives' home. Jun accompanies her. That night, disregarding their surroundings, Jun continues to cling to Shoko in desire. Though Shoko feels deep down that it's wrong, she can't suppress her emotions any longer and secretly takes Jun's hardened cock into her mouth, hiding their act from the watchful eyes of their relatives.