Yui and her husband are sexless. After getting married, she hasn't had her sexual desires fulfilled at all, which makes her furious, so she returned to her parents' home. Initially, she tries to maintain a sister-brother relationship, but gradually develops romantic feelings for her sister... Yui, who gets excited when her ass is groped, tries to force her brother to become an ass lover! Sex where the brother, now an ass lover, desperately tries to please Yui! The situation is irresistible for ass lovers!
