Keiko Shimizu, created by Maikerukun, is a Japanese housewife, devoted to her husband. During high school she was an accomplished volleyball player, which caused her to develop a large body by Japanese standards. She is extremely in love with her husband, Kazuhiro, a hardworking sales consultant. Lately she has had some problems in her love life with her husband, and because of this she found herself in a complicated situation after her husband's younger brother, Gavin, came to live with them. The boy started to fill the place that Keiko's husband should always be, taking advantage of certain occasions to be able to have amorous relations with her, further confusing the Japanese MILF's feelings.