Chizuru Tachibana is the school nurse at Kawanuma East High School, initially known for her cold, expressionless demeanor towards students, earning her the nickname "Absolute Zero Tachibana" (絶対零度の立花, Zettaireido no Tachibana). Despite this detached exterior, she actively sought warmer connections with students, driven by a desire to emulate the approachable nurses depicted in manga. She possesses light grey neck-length hair, typically styled with bangs covering the left side of her face, light grey eyes, and a slender figure with a notably large bust. Her height is 155 cm, weight 45 kg, with measurements of 87 cm (bust), 56 cm (waist), and 85 cm (hips). While working, she typically wears a black top under a white lab coat, cuffed denim jeans, and black ankle-strap heels. She frequently changes into casual outfits like denim shorts with thigh-high stockings or themed costumes, reflecting a personal interest in varied fashion. Her interactions with Koh Tanaka, a third-year student and former student council president, spark significant development. Sharing a hometown connection, a coincidental New Year's encounter leads to them winning a joint trip to Ishigaki Island. During the trip, a series of accidental and intimate situations gradually shift Chizuru's perception of Tanaka beyond the student-teacher dynamic. Although developing feelings, she maintains professional boundaries and rejects his Valentine's Day confession while he remains a student. Following Tanaka's graduation, Chizuru proactively confesses her feelings, explicitly stating the end of their teacher-student relationship and her wish to pursue romance. They become a couple, navigating early romantic experiences including an awkward first visit to a love hotel that highlights their inexperience. Their relationship progresses steadily to marriage, with Chizuru adopting the surname Tanaka (田中 千鶴, Tanaka Chizuru). Later narrative developments depict Chizuru and Koh Tanaka's married life, including their efforts to start a family. By Volume Eight of the manga, they have a daughter together, solidifying their transition from an unconventional romance into an established family unit.