As the daughter of my father's new wife, I became the stepsister 'Momo' san. She is the complete opposite of me, a shut-in, and is an outgoing person who can brightly interact with anyone regardless of their relationship. However, due to her overly open personality, she lives in the house without any guard against me, who isn't treated as a man, wearing a thong that's fully visible. I've never seen a bare ass before, but I kept thinking about my sister-in-law's ass in a perverted way, and one day, I reached my limit…
