Yui started dating Mitsuhiko, whom she met at her part-time job. Mitsuhiko wanted to introduce his first girlfriend to his father, so he invited Yui to their home. Since his wife passed away, Mitsuhiko and Takazou had been living without a woman's presence. Despite his age, Takazou became infatuated with Yui. One day, after Yui had a fight with Mitsuhiko over a trivial matter, Takazou pretended to offer advice but instead made advances towards Yui. Behind the scenes of their innocent love, the illicit physical relationship between Takazou and Yui deepened.
