学生だった義妹は。はじめて会った時、制服姿だった井口は結婚の挨拶にやってきたみゆきを見てそれを思い出し、義妹に劣情を抱いてしまう。そしてその思いは止められず、義妹相手に関係を持ってしまう井口…。My sister-in-law was a student. Iguchi remembers seeing Miyuki in her school uniform when he first met her, and feels a carnal desire for her when she comes to greet him at his wedding. Iguchi can't stop thinking about her, and embarks on a tour of sexual relations with his sister-in-law…
