Usually serious and pure, my mother-in-law Yū-san. One day, she came home drunk, which was fine, but she mistook me for my father and tried to seduce me with her beautiful buttocks! Showing off her smooth, flawless bottom... I'm a man too. There's no way I could resist...! Drunk, she transformed into a lewd woman, and I relentlessly pounded her, finishing inside her thoroughly! From there, a forbidden relationship between Yū-san and me began to unfold...