Shota's father has a woman on the side, so his parents often argue and decided to divorce. Without a mother, his father frequently buys curry from the shop because no one knows how to cook. Not long after, his father said he would bring a new mother home, and Shota was very happy, so his father was reassured. Shota's stepmother is a young, beautiful woman with a much larger butt than his mother's. He quickly became fond of Yui, especially her butt. Shota continuously displayed both inappropriate and innocent behaviors, which made Yui feel both angry and amused. However, Shota became bolder and dared to make love to her right next to her husband! She was very angry, but when she discovered Shota's feelings for her, she changed and wanted to give her whole heart to him.