Himitsu no Gibo Yuugi

Shinichi is a young man who has always harbored a secret desire for his stepmother, Yuriko. When his father is away on business, the two find themselves alone in the house, and the tension between them escalates. Yuriko, aware of Shinichi's feelings, begins to test the boundaries of their relationship, leading to a series of intimate encounters.

As their forbidden game progresses, both Shinichi and Yuriko struggle with the guilt and excitement of their secret. The line between mother and lover blurs, and they must decide how far they are willing to go. Each encounter brings them closer, but also risks exposing their hidden affair to the outside world.