Kana Kimishima is a high school student from a neighboring town who becomes entangled in the violent world of parasites through a unique and dangerous ability she does not fully understand. Physically, she is a striking teenage girl with long black hair that falls to her upper back and brown eyes, and she is frequently seen wearing a pair of pink earmuffs as a signature accessory. Her appearance in the anime was updated from the original manga to give her a more modern and fashionable look, often depicted with a shorter uniform skirt and a style that suggests a contemporary urban teenager.

By nature, Kana possesses a rebellious and impulsive personality, sometimes described as a "bad girl" who keeps company with local delinquents. Despite her tough exterior and carefree attitude toward troublemaking, she has a soft and emotional interior, particularly when it comes to matters of the heart. She is fiercely independent, stubborn, and driven by a deep curiosity about the unknown. These traits are most evident in her obsessive pursuit of Shinichi Izumi, the protagonist, whom she becomes infatuated with after a chance encounter.

Kana’s primary defining characteristic is a rare extrasensory perception that allows her to sense the signals emitted by parasites, the alien creatures that secretly infect and consume humans. This ability is not a conscious choice but an innate, poorly understood gift that sets her apart from other humans. She cannot, however, differentiate between individual signals. While she can sense Shinichi because of his merged existence with the parasite Migi, she is unable to tell him apart from a hostile, fully predatory creature. She initially mistakes this ability for a psychic or romantic link, believing it is a sign that she and Shinichi are destined to be together, which fuels her determination to find him constantly. As she practices using her power to locate Shinichi, she inadvertently becomes more attuned to the parasite network. This backfires when Migi warns Shinichi that Kana is beginning to emit her own signal, making her visible to other parasites, effectively turning her from a tracker into a beacon.

Motivated by a mix of romantic obsession and a desire to feel special, Kana ignores repeated and explicit warnings from Shinichi about the mortal danger she is in. She is deeply convinced that her ability connects her to him on a fated level, and she remains willfully blind to the reality that she is tracking monsters. Her relationship with Shinichi is defined by this tragic imbalance; he tries desperately to push her away for her own safety, while she interprets his concern as a sign of a deeper connection. She also has an ex-boyfriend named Mitsuo, who is part of her delinquent circle and grows intensely jealous of her fixation on Shinichi.

In the narrative, Kana serves as a tragic catalyst for Shinichi’s emotional development. Her role is to illustrate the harsh consequences that can befall ordinary humans who stray too close to the hidden war between humans and parasites. Her death is a pivotal moment in Shinichi's journey. Convinced she can find him, she follows a parasite signal into an industrial area. The signal does not belong to Shinichi but to a predator feeding on a victim. When she realizes her mistake, she tries to flee but is fatally struck from behind. She dies in Shinichi’s arms, and her death leaves him with a profound sense of guilt and emotional trauma that hardens his resolve. The circumstances of her death differ slightly between the manga and the anime; in the original work, she cannot reach Shinichi by phone, while in the anime, she deliberately leaves her phone behind to test her power. Despite her brief presence in the story, her fate leaves a lasting emotional strain on Shinichi and serves as a brutal reminder of the cost of his secret existence.