A girl has been staying over at my apartment, where I live alone at university, for several nights in a row!? An unexpected night of shared sex develops between me and my friend's girlfriend, "Ami-ri"! I initially thought of myself as a safe and reliable guy, but I'm troubled by her completely unsuspecting behavior... Lacking the courage to make a move, I resort to masturbation, and she notices...!? Sex continues until dawn, one after another, in this dreamlike single life!