Kiki is the thirteen-year-old protagonist who leaves her home to complete a year of independent training, a tradition for witches her age. She was born on February 2 and lives with her parents, Kokiri and Okino, and her black cat, Jiji, before departing for the seaside town of Koriko. She has short, dark brown hair that she typically ties back with a large red bow and wears a plain black dress, a practical outfit that initially makes her feel plain and unfashionable compared to the other girls in the city. Her mother encourages her to like herself as she is, a piece of advice that becomes central to her journey.

Kiki is characterized as a strong-willed, curious, and kind-hearted girl, though she can also be stubborn and a little naive. She is upbeat and friendly, but she is not without insecurities, self-doubt, and moments of loneliness as she navigates her new life on her own. Her motivations are rooted in her desire to become a full-fledged witch, but on a deeper level, she seeks to establish her own identity and find her place in the world. She is not driven by a grand ambition but rather by a quiet determination to be self-sufficient and to use her abilities to contribute to her new community.

Upon arriving in Koriko, Kiki's role in the story is defined by her resourcefulness. With only the ability to fly on her broomstick, she starts a delivery service, finding a place to live above a bakery owned by the kind Osono and her husband. Through her deliveries, she connects with various townspeople, including a sweet, elderly woman and her granddaughter, and a friendly boy named Tombo, who is fascinated by aviation. A pivotal relationship is with Ursula, a young artist living in a cabin in the woods. Ursula, who has experienced her own creative slumps, helps Kiki understand that her loss of magic is not a permanent failure but a natural part of growing into one's own talents. Her closest relationship is with her cat, Jiji, who serves as her talking companion and best friend.

The central challenge in Kiki's development is the sudden loss of her ability to fly and to communicate with Jiji. This crisis is not caused by an outside villain but by her own growing self-doubt and burnout. According to the director, magic in the film is not simply a supernatural power but a representation of innate talent and confidence; Kiki had been flying with her parents' magic and needed to learn how to make it her own. Her inability to fly symbolizes a deeper identity crisis, where the thing that defined her and made her special suddenly feels out of reach. Through this struggle, she learns that talent requires conscious effort and that setbacks are a part of finding one's true path.

Her character development culminates when she overcomes her slump not by waiting for her powers to return, but by acting on her courage and compassion. When Tombo is in danger, she desperately commands a street sweeper's brush to fly, successfully rescuing him. In that moment, she stops relying on inherited magic or external validation and uses her own will and purpose to fly, proving that her power is now truly her own. By the end, she has gained a new sense of self-assurance and maturity, becoming a wiser and more integrated member of the town of Koriko.

Kiki's notable abilities are focused and specific. Her primary magical talent is flying on a broomstick. At the start of her journey, this is essentially her only skill, as she has not inherited her mother's talent for potion-making. Her ability to speak with Jiji is also tied to her magical power; as she grows and her magic becomes truly her own, she loses the ability to hear him speak, which symbolizes her psychological maturation and her moving past a projection of her own inner voice. Her real strength lies not in spells, but in her work ethic, resourcefulness, and her kind heart.