VENU-803 Yu Kawakami, 1 night and 2 days left behind by my wife's older sister who suddenly came to me

(I did it...) Yoshinori betrayed his wife. That's because of my sister-in-law, Yuu, who is right in front of me. His wife went on a one-night, two-day trip, and Yoshinori was enjoying the freedom of living alone for the first time in a while. Suddenly, Yuu comes to visit. In reality, Yuu had come to Yoshinori to relieve his frustration... but there was no way Yoshinori would know about that.