Kana Tachibana is a central character in the narrative, introduced as a young woman who escaped from a clandestine research laboratory alongside her friend Neko Kuroha. Her background is marked by immense suffering; during her captivity, she was subjected to experiments that left her paralyzed from the neck down. As a result of this procedure, which involves a device known as a harness, she has lost the ability to walk or use most of her limbs, retaining only limited movement in her left hand. The trauma of her time in the lab has also rendered her unable to speak, forcing her to communicate exclusively through a small keyboard device that synthesizes her typed words into speech.

In terms of appearance, Kana is notably petite and has a distinct, doll-like look. She has blonde hair styled into short twin drill tails, red eyes, and is most often seen wearing a gothic lolita dress and headwear, a fashion choice that further emphasizes her fragile appearance. Her physical helplessness, however, belies a sharp and spirited personality. She is known to be quite feisty, rude, and mouthy, especially towards people she does not know well, such as the protagonist Ryouta Murakami upon their first meeting. This aggressive front is widely understood to be a defense mechanism stemming from her extreme vulnerability and the fear that accompanies her powerless state. Despite this prickly exterior, she is fundamentally a kind and caring individual who is deeply loyal to her friends. She demonstrates a keen ability to read others, often accurately pointing out the romantic feelings between her companions or the perverted intentions of others.

Kana's primary motivation is the protection of her friends, born from a profound sense of gratitude toward Neko Kuroha, who once saved her from being executed by the laboratory when others deemed her powers useless. This act earned Neko Kana’s absolute trust and unwavering loyalty. She uses her abilities to safeguard her new circle, which forms the Astronomy Club, and is willing to endure great personal sacrifice for them, including the loss of her own power.

Her role in the story is multifaceted. She serves as the strategic heart of the group, or its mascot, using her unique foresight ability to identify future threats. Her power allows her to see bizarre deaths that will occur in the near future with one hundred percent certainty if no action is taken. However, these futures are changeable, and her primary function is to foresee the deaths of her friends and send Neko on missions to prevent them. This ability provides the initial connection between the escapees and Ryouta, as it was her premonition that led Neko to save him from a fatal traffic accident. Later in the story, Kana demonstrates a willingness to take a more active role. She chooses to sacrifice her precognitive powers, pressing a specific button on her harness that allows her to move normally but at the cost of her foresight. Although her body has atrophied from years of paralysis, making her weaker than her peers, this decision shows her desire to fight directly for her friends rather than remaining solely as an observer of tragedy.

Kana’s relationships are central to her character development. Her bond with Neko Kuroha is the most significant, defined by mutual protection and deep trust. Her relationship with Ryouta Murakami evolves considerably; she initially dismisses him as a pervert, but after witnessing him repeatedly risk his life for her and Neko, she comes to respect his intelligence and judgment. She forms a notable connection with Kitsuka after transferring into her class, with Kitsuka becoming fiercely loyal to her. The most poignant relationship in her background is with her older sister, Mina Tachibana. After escaping, Kana refuses to involve her family, believing she must protect them from the danger she carries. They are eventually reunited by coincidence, and though Kana initially rejects the reunion, she later reconnects with Mina. Tragically, after accepting her sister’s love, Mina is killed while saving Kana, a loss that profoundly affects her.

Throughout the narrative, Kana undergoes significant character development. She begins as a completely helpless, cynical, and doll-like figure, reliant on others for everything. As the story progresses, she makes the conscious decision to abandon her safety and foresight ability to regain physical mobility, transforming from a passive seer into an active combatant. She trains her body and her killing instinct to better protect her friends, even attempting to fight one of the most powerful antagonists. While she cannot speak on her own, her synthesized voice allows her personality to shine, and she is often the source of blunt, humorous, or insightful commentary. Her journey is one from being a tragic victim of experimentation to a determined survivor who seizes control of her own fate, willing to face danger directly rather than merely predict it.