DRPT-089 A big-bottomed older sister, Mihina, whose sensitivity was dramatically enhanced after her perverted younger brother gave her a strange liquid treatment to her rear end

My Sister’s Rear Is Mine! One day, a younger brother becomes fixated on his sister’s backside and secretly creates a mysterious liquid in his room. It is an amazing formula that greatly heightens sensitivity. The brother sneaks into his sleeping sister’s room and administers the liquid. Unaware of what happened, the sister begins to notice strange sensations and gradually becomes drawn to the heightened pleasure. Emboldened, the brother even prepares an IV and administers a large amount. Overwhelmed by the excessive stimulation, the sister loses her composure and becomes completely consumed by the experience.