光代が熟年離婚して半年が経った。今は娘夫婦と同居して生活に満足している。しかし光代には秘密があった。半年前、光代は離婚が正式に決まりお祝いに酒を飲んでいた。そこに帰宅した娘婿に抱きつきキスをして、娘には黙っているからとセックスしてしまった。それ以降、娘の目を盗んでは娘婿と関係を続けてしまう。ある夜、光代の風呂上がりに娘婿が来てフェラや手マンで快楽に耽る。その後、娘婿は排卵日の妻ともまぐわった。光代はそれを想像しながら野菜で自慰をする。そんな秘密の日々が続いていくと思っていたが…
Six months have passed since Mitsuyo's divorce. She now lives with her daughter and son-in-law and is content with her life. However, Mitsuyo has a secret. Six months ago, Mitsuyo was celebrating her divorce by drinking alcohol. When her son-in-law returned home, she hugged him, kissed him, and had sex with him, promising to keep it a secret from her daughter. Since then, she has continued her affair with her son-in-law whenever her daughter is not around. One night, after Mitsuyo's bath, her son-in-law came over and indulged in oral sex and manual stimulation. Later, he had sex with his wife on her ovulation day. Mitsuyo masturbates with vegetables while imagining this. She thought these secret days would continue indefinitely…

– JavGG.net