Kazuki Kuwanomi is a young woman of above-average height, with a slender figure and an appearance often described as attractive. She has red hair styled in a low bun that resembles a bird’s tail, secured with a small dark blue hair clip. A section of bangs frames the left side of her face. Her eyes are a vivid violet, and she has thin, well-defined eyebrows. Kazuki stands just slightly taller than Tsukasa Mizugaki, highlighting her subtly commanding presence.

Her standard Terminal Service No. 1 uniform consists of a sleeveless white shirt with black collars and trim, paired with separate white sleeves fastened by black cuffs. She wears dark brown slacks that end just above the ankles and completes the look with red heels.

Outside of work, Kazuki’s attire is more relaxed. She has been seen in a light orange long-sleeved shirt, which she typically rolls up to her elbows, combined with dark-colored shorts. During colder seasons, she layers her uniform with a deep green parka jacket for added warmth.

Kazuki Kuwanomi is a dedicated and pragmatic leader at Terminal Service No. 1. She approaches her work with a no-nonsense attitude, balancing empathy for her colleagues with a strong commitment to the tasks at hand. Kazuki values discipline and efficiency, and she has little patience for those who shirk their responsibilities or disrupt the critical mission of the Terminal Service.

Despite her stern professional demeanor, Kazuki demonstrates deep loyalty and affection toward those she cares about, most notably Isla, her former partner. Her devotion to Isla is so profound that she persuaded the entire Terminal Service team to adopt Isla’s personalized approach to retrievals tailoring each case to the client’s emotional needs, even though this method is less efficient and financially impractical. Kazuki is fiercely protective of Isla, always prioritizing her well-being and supporting her choices.

Outside of her professional life, Kazuki is fond of alcohol, though she has an exceptionally low tolerance and struggles to handle her liquor.

Kazuki Kuwanomi originally served as Isla’s Spotter during their time as a team at Terminal Service No. 1. Their partnership came to an end after a failed retrieval involving Michiru Kinushima’s Giftia, an incident that left Kazuki with a serious injury. Blaming herself for the outcome, Kazuki chose to dissolve the partnership to protect both Isla and herself from further harm.

Later in the series, upon noticing the growing bond between Tsukasa Mizugaki and Isla, Kazuki intervenes by reassigning partners having Constance work with Tsukasa while resuming her role as Isla’s Spotter. Though Isla is unaware, Kazuki’s intention is to help Isla realize that distancing herself from Tsukasa for his sake is unnecessary, encouraging Isla to cherish the time she has left.

On Isla’s final day, Kazuki visits the Terminal Service office to share a lighthearted moment with Isla one last time. She takes Isla’s ID badge and urges Isla and Tsukasa to spend the day together without worrying about work. That evening, Kazuki and Constance discreetly follow the pair to the amusement park to watch over them. After Isla’s deactivation, Kazuki thanks Tsukasa for staying by Isla’s side until the end, offering him comfort as he breaks down in grief.

In the epilogue, Kazuki welcomes Tsukasa back following his nine-month training period and introduces him to his new, unnamed partner for his continued work at Terminal Service.

Kazuki’s given name, Kazuki (カヅキ), is written in katakana, a script often used for names to give a modern or neutral tone. Her surname, Kuwanomi (桑乃実), combines the kanji 桑 (kuwa), meaning “mulberry,” 乃 (no), a possessive particle often seen in names, and 実 (mi), meaning “fruit” or “seed.” Together, her surname can be interpreted as “fruit of the mulberry tree.”