Yui lives an ordinary life with her earnest husband. One day, Yui is called by her husband's boss, Sada, who tells her that her husband has received bribes from a client. She begs him to do anything for her husband, but Sada says, "I don't need the part that's been used," and starts playing with Yui's anal. Then, a few days later, Sada comes to her house and violates Yui's anal right next to her husband as he sleeps. However, that is just the beginning, and Yui never even imagined that she would awaken to the pleasure of anal sex...