Chizuko is a girl with long braided hair who wears glasses and wear her school's uniform.
Chizuko has a shy, introverted personality. She was seen in the beginning being harassed by a man in the subway, when Hinomaru protected her. Since then, she looked for him, until she found the sumo club. She later joined after sharing videos of their inter-high qualifiers to the school, as a way to repay Hinomaru, showing a great deal of knowledge acquired from books, especially when it comes to history, because Hinomaru is really interested in, and good at Japanese history.
- Her hobby is painting, especially with watercolors.
- She's deceptively fast on her feet
- She and her sister are polar opposites, but they still are close.