Today is my first date at home with my girlfriend, Yaya-chan. When I go up to the room, she asks me, looking up, "Is your mother not home today?" Could this be my chance to lose my virginity...?! Or so I thought. Then I got a call from my senior. "You're home now, right? I heard you got a girlfriend? Let me see her." He's a real nuisance, but I don't want to turn him down, so I reluctantly call him over, and he shows up...