Yumeru is living alone in Tokyo for two weeks during her summer cram school course. Although she is excited about living alone for the first time, she is worried about the amount of garbage spilling out from the entrance and balcony of the neighboring room, and the stench that stings her nose. "Do you want to help me clean up?" she asks, mustering up her courage, when her dirty brother comes out, masturbating continuously even after cumming, without cleaning up after himself. While she is making him clean up, he gets aroused by the sight of her uniform panties and attacks her from behind...