Grade: First Year (Later Second Year)

Age: 15-16 ( Born: May 5th)

Personality traits: Energetic, lively, hard-working and innocent

Position: Head of Judo Club

Mutsumi is a pretty girl with long black hair that reaches halfway down her back. In all her appearances, she wears it in a ponytail starting from the upper-back part of her head. She is in excellent shape and her best friend Chiri has noted she has nicely shaped breasts.

Mutsumi is a kind and energetic girl who makes friends easily among both boys and girls. She is known as a moodmaker due to her cheerful and uplifting personality. She is also very innocent and pure-hearted, often misinterpreting the perverted comments of Aria Shichijou and Shino Amakusa. However, while she excels at sports and physical education, she is a poor student in other subjects. She has also admitted to dozing off in class and finds it hard to sit still for long periods of time.