Eimi, who came to Tokyo after graduating from junior high school, recommends her sister Yu, who lives in her hometown of Shiga, to live in Tokyo. She refused at first, but for some reason she accepted that she suddenly came to Tokyo, but soon after she moved she went missing. Meanwhile, Eimi meets Hiyori, whose sister is also missing. Eventually, police contacted Eimi that a young woman's body was found in her hometown of Lake Biwa, but the body was Hiyori's sister, not Yu.