Yui has no sex with her husband. Since getting married, she has felt angry that her sexual desires have not been satisfied at all, so she returns to her parents' house. At first, she tries to maintain a relationship as sister and brother, but gradually she begins to have romantic feelings for her sister... Yui gets excited when her butt is rubbed, so she gives her brother a buttjob to force him to like butts! Her brother, who has become a butt lover, desperately tries to make Yui feel good in sex! Full of situations that butt lovers will love!