After Yui's father remarried Kasumi Horai and passed away, Yui and her stepmother lived together like friends despite their age difference. Yui couldn't forget the blissful expression she saw on Kasumi Horai when she was bound. One day, they both realized they had the same feelings for each other. They knew it was wrong but couldn't resist. They tested and confirmed their feelings through intense lesbian play, hard spanking, suspension bondage, and enema.
