Kozue lives with her husband and her daughter's family. One night, she finds herself alone with her son-in-law, Shota. Under the influence of alcohol, Shota confesses his feelings for Kozue and gives in to his uncontrollable desire. Saying, "It'd be a waste to leave my sexy stepmother untouched," he dives into forbidden passion. Though shocked and conflicted, Kozue's body—long deprived of intimacy—begins to respond to her son-in-law's touch. This shocking affair begins here.