A childhood friend of Jinta, Naruko, Asumu, Tetsudo and Meiko. Chiriko is the quiet observer of the group and has an extremely serious and logical personality. She and Atsumu are the only two that remain close friends as the years pass and attend the same elite high school. The two are seen together so often that they are mistaken for lovers by their classmates and a shopkeeper. She has feelings for Atsumu, as she shows contempt whenever she sees that he has not gotten over Meiko's death. She keeps the hairpin Atsumu threw away after being rejected by Meiko, even wearing it when alone. At times, she plays the voice of reason for Atsumu as well as the role of a guardian. She knew of his guilt over Meiko's death and suspected that he was crossdressing as a means of coping.
She can be critical of others, and in particular scolds Naruko for her habit of following others. She often sketches while idle, even doodling Atsumu wearing Meiko's sundress. Chiriko still feels indifferent over Meiko's return, doubting what her intentions are or if she has truly forgiven everyone. She admits to Naruko that she is in love with Atsumu, but believes that he will never love her back because she cannot win against Meiko. Chiriko feels that he is irreplaceable to her, thus she aids the effort to have Meiko achieve nirvana.