"I want a massage..." her father-in-law suddenly muttered after he retired and was always spacing out. Matsuri felt a little reluctant to ask him, but since it was a former chiropractor who would do it, she didn't have to go to the store and she was tired from housework, so she asked him. However, her father-in-law was not just a chiropractor... With his years of experience and techniques, Matsuri's body was so sensitive that she couldn't stop trembling every time he touched her, and she fell into the bored old man's sexual development that continued all day every day...