Kanon is a central figure in the narrative, a young teenage girl whose abduction becomes the catalyst for the dramatic collapse of the secret society that takes her. Physically, she is described as a beautiful girl of about fourteen years of age, with black hair that reaches her waist and black eyes. Her height is recorded as 150 centimeters. She attends a prestigious all-girls school, which has provided her with a refined upbringing, including the ability to play the organ and piano and to sing hymns; she also has training in swimming, which allows her to hold her breath for long periods of time. Her title within the Light Club, her captors, is "the Imprisoned White Lily".

Kanon exhibits a complex and somewhat contradictory personality. On the one hand, she displays a serene and exceptionally accepting nature. After being drugged and kidnapped, she does not panic or beg; instead, her primary coping mechanism is to retreat into sleep to make "unhappy times go by faster". She is described as a natural airhead and a romantic, predisposed to accept what she is told rather than question her circumstances, a trait that may stem from a life of being trained to be a perfect, unquestioning lady. This naivety, however, coexists with a quiet but firm will. She is not afraid to express her needs, directly asking her robot custodian for food or the use of a piano. Her outward submissiveness belies an inner world rich with romantic ideals and a deep, almost self-loathing belief that people will eventually grow to hate her, making her resigned to a fate she cannot control.

Kanon's primary motivation is not escape, but connection. More than being rescued, she longs to be perceived as a genuine person rather than an object of beauty or a "missy" of high society. Trapped in the club's hideout, she finds this connection not with her human captors, but with Litchi, the club's robot. Her role in the story is to serve as the "beautiful thing" the robot was programmed to retrieve, but she quickly transforms into the club's worshipped goddess and, more significantly, the teacher of humanity to the mechanical Litchi. While the club descends into paranoid violence, Kanon remains in her suspended state, awakening from her chosen somnolence only when the situation becomes critical. She explains concepts like sadness and love to Litchi, and becomes the moral anchor that causes him to defy his programming and refuse to kill. She is the key to the leader Zera's prophecy, the girl who holds the fate of the club, though she never actively seeks this power.

Kanon's most significant relationship is, by far, with Litchi. Her feelings for the robot grow from a transactional friendship, where she asks him for necessities, into a genuine, tragic romance. She teaches him how to be romantic and, in turn, learns that he is capable of protecting her in a way no one else has. This bond is the emotional heart of the story, and her decision to jump back down to be with him when escape is possible demonstrates that for her, living without him is not worth it. In contrast, her relationships with the human boys of the Light Club are distant. She is an object of worship for their leader, Zera, and a witness to their brutal self-destruction, but she remains emotionally detached from them, focusing her energy entirely on Litchi.

Over the course of the narrative, Kanon evolves from a passive victim who sleeps to avoid reality into an active agent in her own and Litchi's fate. Initially, she accepts her kidnapping, her potential death, and even the bizarre plan to remake her as a machine with little resistance. However, her development is tied to her growing love for Litchi. When he is in danger or when she has the chance to save him, she acts decisively, such as when she gives him the last lychee fruit to refuel him, leading to his final burst of protective violence. By the end, she is not the sleeping, resigned girl but the sole survivor, walking away from the carnage while playing a requiem on the piano, forever scarred but having experienced genuine love.

While Kanon does not possess superhuman abilities, her talents are notable. Her skill as a pianist is her primary means of emotional expression, allowing her to communicate feelings she cannot articulate, from relief to profound sadness. Her training as a swimmer grants her the remarkable ability to hold her breath for extended periods, a skill that ultimately allows her to survive an attempt on her life by drowning and to later revive Litchi. Her greatest ability, however, is her profound, almost irrational acceptance, which allows her to navigate a situation of extreme horror without breaking, and her capacity to teach humanity to a being who was never supposed to have it.