Haruko Shidō (四道 晴子 Shidō Haruko) is the little sister of Matagu and the comedy relief in Please Twins!.
She is usually very bubbly and hyperactive with a very immature personality and while she acknowledges that her brother is a pervert, she seems completely oblivious to such mature matters. She attends class 1A. She, Akina Sagawa and Futaba Mashita greet Miina and Karen on their first day of school.