Chitose Hibiya is the landlady of the apartment complex where the main character Hideki Motosuwa resides. She is a young woman with a calm, friendly, and generous demeanor, consistently greeting her tenants with a warm smile and offering assistance without judgment. Physically, Chitose is of average height with long, dark-lavender hair and dark-purple eyes, and she is often seen maintaining the property with a broom in hand. She appears to be in her late twenties.

Behind her ordinary role as a landlady lies a much deeper and more significant past. Chitose was formerly a scientist employed by Piffle Princess Enterprises, where she worked alongside her late husband, Ichiro Mihara. The couple was instrumental in the development of persocom technology, the highly advanced personal computers that take human form. Because Chitose was unable to have children, her husband created the Chobits series—two unique and powerful persocoms named Freya and Elda (who later comes to be known as Chi)—to be her daughters. Chitose is thus the de facto mother of Chi, the central persocom of the story. Her husband has since passed away, leaving her the apartment building as a source of income.

In the present, Chitose serves as a quiet guardian and guide for Chi and Hideki. She often gifts Chi elaborate outfits, which are later revealed to be clothes from the time she spent with both of her persocom daughters. Knowing that Chi has lost her memory and must find her own path, Chitose writes and illustrates a children’s book series titled A City with No People. The story within these books is designed to help Chi understand the concept of love and lead her to find the "person just for her," a crucial step in her development. Chitose promised her husband that she would only observe Chi from a distance and not intervene directly, a promise she struggles to keep as her maternal affection makes her want to help more. She respects this vow by influencing Chi subtly, most notably through her books and through timely, indirect assistance.

Chitose is highly intelligent and resourceful, possessing extensive scientific knowledge about persocoms that she uses on rare occasions, such as repairing the petite persocom Sumomo. Her apartment contains a secret, high-tech room from which she can monitor events in the city. Her primary motivation throughout the story is to see Chi find true happiness with a person who will love her for who she is, even if it means Chi never remembers her true origin as her daughter.

Chitose's key relationships are defined by her past and her role as a caretaker. She shares a warm rapport with Hideki, often helping him with meals and advice, and he trusts her implicitly. However, her most profound connection is with Chi, whom she sees as a daughter. She also has a deep, enduring love for her deceased husband, frequently addressing him in quiet moments as she observes the events unfolding that will decide Chi's fate. Over the course of the narrative, Chitose does not undergo a dramatic personal change, but her behind-the-scenes efforts and the revelation of her tragic, loving backstory reshape the audience’s understanding of her character from a kind landlady to a pivotal figure in the series' central mystery. Her notable abilities include her deep technical knowledge of persocom hardware and software, her skill as an author and illustrator, and her patient, long-term planning as she orchestrates an environment for Chi to learn and grow on her own terms.