Infinity and Yui Natsuhara, college friends, often visit, using proximity as an excuse. Their host's lust grows, fueled by the girls' unguarded moments. Part 3 finds Yui, in a tiny nightie, unaware of the throbbing desire she stirs. Infinity, catching him staring, playfully teases, her nipples hardening under his gaze. He can't resist, approaching her, hands exploring her curves. She moans softly, fingers sliding into her already wet pussy, inviting him in.