Naho married her husband and lives with him and her father-in-law. Although the sex with her husband was bland, Naho was satisfied, but as time went by, the number of days and times of the act decreased. After all, Naho's libido was strong and her husband's stamina was at its limit, so she had to resort to masturbation during her alone time. Her father-in-law observed such a married life, enjoyed it, and kept a diary. From some point on, Naho's clothing changed. The exposure increased, and she started wearing clothes that were mistaken for no bra? No pants? At first, she thought it was part of the act with her son, but looking back at the diary, she noticed that she started dressing like that around the time the act with her son decreased and disappeared. One day, when her husband went to work and her father-in-law went out on an errand, she was enjoying her alone masturbation time when her father-in-law, who had skipped the errand, came back. Her father-in-law, who had been watching Naho engrossed in masturbation with a surprised expression, got excited at Naho's desperate panting and trapped her. Her father-in-law's seasoned caresses were fierce, especially the persistent cunnilingus that made her come several times. His thing was bigger, harder, and more curved than her husband's, and Naho reached the peak the moment she was penetrated. A few days later, when the family was out and Naho was alone, she dizzily took out her father-in-law's underwear from the laundry basket and quietly sniffed it. As she remembered the act with her father-in-law and ran her fingers along her crotch, her underwear was wet in a lewd way...