Kabu hails from the Magic Kingdom as a magical assistant possessing shape-changing abilities. Initially appearing as a crow, he was dispatched to Earth by Sally's father to retrieve her. Upon arrival, he adopted the permanent form of a five-year-old boy, seamlessly blending into human society by posing as Sally's younger brother.

His core mission involves supporting Sally during her Earthly stay while vigilantly safeguarding the secret of her magical identity. Across all documented media, encompassing both the original and sequel series, Kabu consistently exhibits a mischievous personality. This trait actively manifests through frequent pranks targeting Sally, her human friends Yoshiko and Sumire, and various other characters. His penchant for mischief rivals that of the Hanamura Triplets and the witch girl Poron, frequently triggering unpredictable complications or chaotic situations.

In the sequel series, set years later, Kabu returns to Earth alongside Sally, resuming his role as her assistant. He actively participates in new adventures while maintaining his characteristic prankster behavior, now directing his antics towards additional characters like Poron and Dabdab the cat. His actions persistently contribute to scenarios involving chaotic magical mishaps.

Throughout Sally's transition to becoming queen of the Magic Kingdom, depicted in the sequel series finale and the OVA "Mother's Love is Eternal," Kabu remains present. He continues his established behavioral patterns without undergoing significant personal evolution. Official media offers no explicit development or deeper exploration of his background; his mischievous nature and steadfast supportive function endure unchanged across all appearances.