Hana is an anthropomorphized anatomical model that comes to reside at the Ayase residence. Her design is distinctive, reflecting her nature as a female human body model. The right half of her form displays exposed muscle tissue, while the left half retains the appearance of skin. On the skin side, she has a tied-back hairstyle and one closed eye. Unlike her counterpart, Taro, Hana lacks limbs and is unable to move on her own, typically being held upright by a round base stand attached to her torso. After she begins living with the Ayase family, she is given a beanie and a shirt to wear for modesty.

In terms of personality, Hana is defined by her quiet and reserved nature. She remains completely silent around people other than Taro, which could be attributed to shyness or possibly a limitation that only allows her to communicate with another anatomical model. Her most prominent characteristic is her deep, affectionate, and reciprocated relationship with Taro, to whom she is completely devoted. Despite her silence with others, she becomes emotionally expressive when interacting with her partner.

Hana's primary motivation is her bond with Taro. She was initially resigned to being discarded and forgotten, having seemingly accepted her fate as an old object no longer needed. However, encountering Taro and experiencing his devotion gives her a new purpose. Her role in the story centers on this relationship, as the main characters become involved in helping the pair stay together. She is first encountered at a junkyard, where Taro frantically searches for her. Hana initially begs Taro to leave her, feeling she is not worth the trouble, but she is moved by his passionate feelings for her. The protagonists offer her a place to stay at the Ayase residence so that she and Taro can continue their relationship, an offer she accepts. Her storyline provides a more heartfelt and unusual subplot within the larger narrative.

Her most important relationship is undoubtedly with Taro, her lover. She also develops a functional relationship with the Ayase household, particularly with Momo Ayase and Seiko Ayase, who agree to shelter her. While she does not directly interact much with them, this arrangement is crucial for her survival and happiness. Hana does not undergo a dramatic transformation, but her situation develops from one of abandonment and despair to one of hope and security thanks to her relationship with Taro and the kindness of others. In terms of abilities, Hana possesses no exceptional powers or combat skills. Her limitations are physical, as she cannot move or speak on her own, and her ability to interact with the world is almost entirely dependent on Taro and the humans who help her.