I'm Murata, a member of the university's ekiden team. I live in this dorm with about ten other teammates. We don't get along badly, but honestly, I know I don't really fit in with them. To put it simply, they're all extroverts, and I'm an introvert. But life in this dorm is fun, and that's thanks to our dorm mother, Minami-san. She's cheerful, friendly, and treats me just like everyone else. She's beautiful, has huge breasts, and to be honest, I've used her as my wank material many times. On the other hand, the extroverted guys tease her and treat her roughly, casually groping her breasts. I'm so envious of those big, soft breasts being kneaded by everyone, but I don't have the guts to do that on my own. The most I can do is join in when everyone surrounds her to grope her, and casually touch her breasts. I secretly admire those massive tits, and while trembling, I savor their softness, blending in with everyone's messy hands. Later, I masturbate alone, remembering the sensation left on my hand. This is the story of the day I finally got leftover sex with my dream Minami-san, thanks to the extroverts.