Chisato Chikaishi is a classmate and childhood friend of the protagonist, Kazuya Kagami, and serves as a recurring character throughout the story. She has a plain but not unattractive appearance, with thick eyebrows and black hair that she typically ties into a braid, complemented by a pair of glasses. When she removes her glasses and lets her hair down, she is revealed to be quite pretty. Her hairstyle originally featured bangs, but she later changes to a style that exposes her forehead, with the bangs hanging at each side of her face. In a gender-swapped scenario, her face remains the same, but her hair becomes short.

In terms of personality, Chisato is studious, prudent, and caring, often taking on a responsible role among her peers. She has a strong aversion to perverted or extremely unpleasant situations, in which she will resort to violence, usually with a harisen fan. Her relationship with Kazuya is particularly notable; she is often harsh and sometimes violent toward him, but this behavior stems from genuine care and concern for his well-being. She is also a modest and simple person, as demonstrated when a desire to go to Kazuya's house to study unintentionally creates an amasogi, a type of curse-born spirit. The spirit is dispelled simply when Kazuya extends the invitation, satisfying her wish.

Chisato has been friends with Kazuya since they were very young. A formative memory from their childhood involves them playing house with dolls. When other children teased Kazuya for playing a father role, he became reluctant to continue. In response, Chisato kept one doll while giving the other to Kazuya, symbolically preserving their connection and promising to play again in the future. Since then, she has remained close to him, frequently lecturing him and helping him with his schoolwork. Her role in the story is primarily that of a normal human friend who gets drawn into the supernatural events surrounding Kazuya and his tsukumogami, Kiriha. She is not an exorcist or a spiritual being, but her connection to Kazuya often places her in the path of amasogi incidents.

Her key relationships center on Kazuya, toward whom she has clear but often unspoken romantic feelings. She is known to reject other suitors, stating that she already likes someone else, though she is reluctant to confess directly to Kazuya. She also interacts with the wider cast, including Kiriha, with whom she shares a complicated dynamic regarding Kazuya's attention. As a normal human, Chisato possesses no inherent supernatural abilities. However, she is shown to be quite skilled at wielding a harisen, a large paper fan, as a comedic weapon. In the dream world, she is given a special charm by the local deity Kukuri, which temporarily allows her to summon and command an amasogi of her own. Over the course of the narrative, while she does not gain combat-oriented development, she remains a grounding presence for Kazuya, representing his ordinary life and his emotional ties to the human world. Her modest desires and straightforward personality continue to define her actions, and she remains a steadfast, if sometimes volatile, source of support for him.