Beautiful mature woman, Chihiro Akino, has finally let her husband have sex! Chihiro and her husband, Chikiji, have not been able to have a satisfying sexual relationship recently due to his erectile dysfunction. One day, feeling guilty for making Chihiro feel lonely, Chikiji calls his friend, Yamaguchi. "Maybe something will change if he sees Chihiro having sex with another man..." Chikiji is determined to make love with his wife again. However, Chihiro does not know that Chikiji has made such a decision, or that Yamaguchi also has an anal fetish.