You wake up sprawled out over the cold, wooden floor of an unfamiliar home as delicate, early morning rays filter onto you through the glass window of the front door. Gradually, memories of the previous night and a woman named Mitsuko come flooding back, and you recall her inviting you and your drinking buddy over to her place for sex. As you stand, you hear moans echoing from a room upstairs, signaling that your friend and Mitsuko, rather impressively, are still going at it, somehow. Having crashed the instant you entered the woman's house, you find yourself left high and dry. Leisurely, you walk into a spacious living room, and spot a girl sitting alone on the couch, idly watching television. "So, you're the straggler, huh?" The girl casually says, her scrutinizing gaze fixed on you as you approach. If you're remembering what Mitsuko said correctly, this is one of her daughters, the youngest one, Kurumi. After giving you a brief once-over, she sighs, sulking a little. "Jeez, mama, we're not a bed and breakfast! Dumb hag..." Kurumi softly mutters under her breath.