Kaoru Hanawa is a central character in the anime Tamayura: Hitotose, serving as the childhood friend and a key pillar of support for the protagonist, Fuu Sawatari. She is a high school girl with reddish-brown hair that she typically wears in a ponytail, a style that has become a recognizable part of her appearance.

Kaoru's personality is defined by her reliability and levelheaded nature, often acting as a calm and grounding presence among her more dreamy or excitable friends. She has a caring, almost sisterly demeanor towards Fuu, frequently watching over her and affectionately teasing her, especially when Fuu's clumsy nature or passion for photography causes her to lose awareness of her surroundings. One of her most distinctive traits is a self-proclaimed smell fetish, a fascination with scents that leads her to take an interest in various aromas and to create her own blends of potpourri as a hobby. This unique characteristic aligns with the series' theme of associating each of the four main friends with a different sense, with Kaoru representing smell. Her name itself, which can mean fragrance, complements this trait.

Within the story, Kaoru's primary role is that of an emotional anchor and a catalyst for Fuu's social life. Having known Fuu from childhood visits to the town of Takehara before Fuu's family moved away, Kaoru warmly welcomes her back and actively encourages the initially shy Fuu to make new friends and adjust to their high school. She is a core member of the close-knit group of four friends that includes Fuu, Norie Okazaki, and Maon Sakurada, and she is consistently present for their shared activities, from participating in the photography club to joining the often-lengthy exploratory trips organized by her older sister. A significant relationship in her life is with her older sister, Sayomi Hanawa, who is much more adventurous and spontaneous, often dragging the group on her expeditions, much to Kaoru's exasperation.

Throughout the series, Kaoru experiences development, particularly concerning her own future. While her friends begin to develop clearer aspirations—Fuu with photography, Norie with baking, and Maon with her artistic pursuits—Kaoru initially feels uncertain about her own path. This uncertainty is a key part of her coming-of-age story. However, she demonstrates strong organizational skills and a natural talent for bringing people together, a fact highlighted when she single-handedly conceives and coordinates the We Exhibition. This event, designed to showcase her friends' talents and hobbies, requires significant planning skills like venue booking and layout design, subtly pointing toward her potential strengths. Eventually, reflecting on her desire to help others and her experiences observing weddings, she decides on a career path as a wedding planner. This journey shows her growth from a supportive friend into someone who confidently charts her own course while still being the reliable, big-sisterly figure for Fuu and the others.