Mei, the older sister, lost both parents at a young age and raised her younger brother as a surrogate mother. Her younger brother grew into a young man who adored her. He successfully entered university, living in a dorm while her older sister stayed behind to work in the local area. Mei panics when her younger brother returns home after a long time. "Sorry, we only have one futon tonight... Is it okay?" The single rice cracker futon brings back memories of the past. The smell of her nape nearby. The sound of her heartbeat. Oh, I can't take it anymore... She's turned on by her older sister.