Takanashi Reiko

She is the daughter of a prominent local businessman and the president of the PTA. Because of this, she has a high sense of pride and is always aware of the fact that she is a Takanashi. She strictly educates her daughter, Otoha, and encourages her to study hard every day. She has divorced her husband and returned to her parents' home in the countryside with Otoha. She is the protagonist's older sister and considers him to be a disgrace to the family.