Haruko is the younger sister of Matagu Shidou, who constantly keeps an eye on her and showers her with affection. She is also a friend and classmate of Karen Onodera and Miina Miyafuji. Haruko tends to be somewhat naive and is always cheerful and full of energy.
After Miina and Karen figure out who Haruko's sister is, Miina runs away and spends some time living at Haruko's home.









