Description: Yoko (Mirai Shida), a first-year high-school student, has been the victim of her older sister, Makiko  Show Full Description... (Yu Yamada), since they were little girls. Makiko treats Yoko as her personal servant, making her feel useless and stupid. Yoko has tried to tell others that Makiko is evil, but the older girl is good at showing a benevolent face to the world, so no one believes Yoko. Makiko becomes more demanding the older they get, even using Yoko to get boyfriends for her.
One morning, when Yoko leaves home for school, she sees Makiko talking to Yoko's boyfriend, who is there waiting for her. Makiko has told him something embarrassing about Yoko, and Yoko can no longer stand it.