Kiki, a spirited young witch, embarks on her journey of independence, a rite of passage for all witches, with her charming talking black cat, Jiji, by her side. With her mother's insistence, she takes along her trusty old broomstick to navigate the skies. As Kiki sets off into the night, she seeks a new town where she can establish herself. During her travels, she encounters another witch and her cat, whom she finds somewhat pretentious, igniting a curiosity within her about what her own unique abilities might be.
Upon discovering the town of Koriko, Kiki inadvertently disrupts traffic while flying, drawing the attention of a policeman. Fortunately, she is aided by a friendly boy named Tombo who helps her escape the awkward situation.
Eager to find a place to call home and establish a livelihood, Kiki stumbles upon the Gutiokipanja bakery, run by the warm-hearted Osono and her husband, Fukuo, who are soon expecting a child. Osono graciously offers Kiki a room above the bakery, and thus begins her venture into entrepreneurship with the creation of the "Witch Delivery Service," using her broomstick to deliver goods. Her first task involves delivering a small stuffed toy resembling Jiji. However, as she navigates the winds, a flock of crows attacks, leading her to misplace the toy. With quick thinking, Jiji pretends to be the toy until Kiki can recover it, ultimately finding it in the care of a young artist named Ursula, who returns it after repair.
The next day, Tombo invites Kiki to join his aviation club. Yet, her schedule fills up with deliveries, and a sudden thunderstorm dissuades her from attending. Following this, she falls ill, making her absence from social events even more noticeable. Osono lovingly looks after Kiki until she recovers, even secretly arranging for her to reconnect with Tombo through a special delivery addressed to him. Kiki expresses her regret about missing out on his gathering, and Tombo offers her an exhilarating test ride on his bicycle-turned-flying machine, causing Kiki to develop feelings for him, although she remains put off by his friends.
However, Kiki soon faces a daunting challenge—the inability to understand Jiji and the loss of her flying skills, forcing her to temporarily halt her delivery business. In her time of need, Ursula visits and invites her to spend time at her house. The two share a bond, leading Ursula to recognize that Kiki's struggles stem from a creative block, urging her to search for new inspiration to reclaim her powers.
An unexpected turn occurs when Kiki witnesses a televised airship accident, where Tombo bravely attempts to secure the dirigible amid strong winds. Spurred by a rush of determination, Kiki rushes to the scene, borrowing a broom from a local shopkeeper. With renewed confidence, she regains her flying abilities, successfully rescuing Tombo. Rejuvenated by this triumph, Kiki resumes her delivery service and joyfully writes a letter home to share that both she and Jiji are content in their new adventure.
