Hikaru, a wife, decides to visit her sister in hospital and accompany her husband on a business trip. Her brother-in-law is kind enough to let her use his vacant room until her sister is released from the hospital. When he meets her for the first time in a long time, he begins to have naughty fantasies about Hikaru, who has grown into a pure and mature woman. While he is taking care of her diligently, unaware of his brother-in-law's feelings, he ends up coming on to him. Hikaru, who is not one to say no strongly, is unable to resist her brother-in-law's fierce advances, and before she knows it, she is squirting as their relationship deepens and she feels so much.