Reika is married to a man who has a child from a previous marriage. Although she has a good relationship with her husband, her stepson Yuki is an introvert and her relationship with him has not been going well. Then, at her husband's suggestion, they go on a trip to a hot spring, where the two finally begin to open up to each other, but... Yuki, who secretly harbors feelings for her as a member of the opposite sex, can't hold back and attacks her while she is asleep. Reika writhes violently as he caresses her with the force of his youth. The sex is a perfect match for her, something she has never felt with her husband, and her body unconsciously throbs for his cock...