Chizuru, nicknamed Chii-chan, is a tall girl who first appears as a classmate of Shuichi when they both enter junior high school. She is Momoko's childhood friend, and has a stylish demeanor, highlighted by her tall stature and long hair, which captivates both Shuichi and Yoshino when they first meet her. Chizuru is described as a free spirit, someone who enjoys doing unconventional, often outrageous things which surprise those around her. An outspoken and eccentric character, she is shown to have enough confidence to wear a boy's uniform, or unapproved street clothes, whenever she feels like it to school. She states that she just enjoys being herself and that other opinions are not important when making her decisions. She frequently acts without thinking, and as a result projects a childish personality. Her impulsive behavior sometimes gets her in trouble with other characters, but she quickly becomes ashamed when she realizes the consequences of her actions. Even if a lot of her actions do bring odd looks, she continues to do whatever she feels like doing, much to the disappointment of her friend Momoko Shirai. She tries to be everyone's friend, though Saori strongly dislikes her impulsiveness. Chizuru joins the girls' basketball team in junior high. Her family runs a soba restaurant.
Chizuru is introduced in the first episode as a classmate of Nitori Shuuichi, Yoshino Takatsuki, Saori Chiba, Momoko Shirai, Kanako Sasa, and Makoto Ariga. She is outspoken and has no qualms about wearing a boy's school uniform, even though she is a girl. She later states that she does not care of other opinions and is willing to fight those who question or give her a hard time for her oddness.
Throughout the series she is shown to be good friends with the group and especially with Saori Chiba, because of her loyalty, to the point way of saying good things. When Suuichi comes to her for advice on crossdressing, she is unable to decisively give him an answer on whether it is wrong or right, and mentions that one should do what one wants.