Mature lesbian step-sisters beautiful lustful body... slutty intertwining bodily fluids and their fate

Yu and Nanako are close step-sisters. The two married each other and left the house, but returned to their parents' home due to violence from their husbands. It's been a while since the sisters were not in the water, and the memories were blooming, and we ended up taking a bath together like we had in the past. Perhaps due to alcoholic drinks, Nanako asks her sister Yu to show her how she masturbates. Yuu is confused, but gradually he becomes serious about fingering, and his sister, who was watching it, gets excited...