On their fifth wedding anniversary, the Shio family visited a high-end restaurant. There, his wife Yuriko received a discounted massage ticket from an employee. At her husband's urging, Yuriko immediately went to the massage parlor. Initially, she relaxed with the oil-based treatment, but gradually the masseuse's fingers moved from her crotch towards her anus, and told that it was a medical procedure, she couldn't resist and ended up being penetrated there. Since then, Yuriko felt unsatisfied with vaginal intercourse with her husband and visited the massage parlor again...
