夏休みに1週間、旦那の実家に法事で泊まることになったKAORI夫妻。夫の兄と甥っ子が夫妻を出迎える。タチの悪い甥っ子はKAORIに目をつけ、旦那がお風呂に入っている間にエロ行為を迫って来る…最初は戸惑いイヤがるKAORIだが、いつしか甥に求められると快楽を覚えるようになってしまう…。Mr. and Mrs. KAORI are staying with their parents for a week during summer vacation for a legal matter. The husband's brother and nephew greet the couple. The nephew, who has a bad temper, takes an interest in KAORI and tries to have sex with her while her husband is taking a bath… KAORI is confused and reluctant at first, but she begins to feel pleasure when she is desired by her nephew…