Doremi Harukaze identifies as an unlucky elementary schoolgirl. She possesses fair skin, long red hair typically styled in large twin buns secured with pink scrunchies (one featuring a yellow music note), short bangs, and a distinctive upward tuft. Her eyes are round and mulberry-colored. Her initial wardrobe includes a carnation pink T-shirt layered over a purple tank top with loose dull pink denim shorts, pale pink socks, and fuchsia-and-white sneakers with peach shoelaces. Later attire evolves to incorporate a purple zipped vest with pockets, lilac shorts, a belt, and knee-length socks with white shoelaces.

Her personality exhibits chronic clumsiness, impulsiveness, and a tendency toward fleeting jealousy over trivial matters, though these feelings dissipate quickly unless deeply offended. A self-proclaimed "big eater" drawn to romance, she frequently develops crushes on boys, adopting their hobbies to forge connections. Despite these traits, she possesses strong empathy and determination, often intervening to help others regardless of personal feelings. This tenacity fosters numerous friendships, though her actions are occasionally misinterpreted, causing frustration. Recurring motifs involve consistently ruined ice cream experiences and missed steak-eating opportunities.

Her background reveals an early curiosity about the world and interest in magic. A childhood piano recital ended disastrously due to forgotten lessons, but provided her first taste of steak, which became her favorite food. Her mother noted similarities between Doremi's childhood behavior and her younger sister Pop's early personality. Initially jealous of Pop's perceived maturity and attention, Doremi attempted distance, contributing to their strained early relationship.

Her journey as a witch apprentice begins upon discovering Majo Rika's true identity, accidentally triggering a curse that transforms the witch into a frog. To reverse this, she becomes a witch apprentice, receiving a pink bean-shaped crystal ball and the fairy companion Dodo. As the first apprentice, she is often regarded as the group leader. Her spells frequently fail or backfire due to distractions like hunger or emotional fluctuations, especially early in training. Signature incantations include the transformation phrase "Pretty Witch Doremicchi!" and spells like "Pirika Pirilala Poporina Peperuto!" and "Magical Stage Pirika Pirilala, Nobiyaka ni!".

Relationships form a core aspect of her development. Her long-standing friendship with Hazuki Fujiwara, dating back to kindergarten, features mutual support where Doremi provides encouragement and Hazuki offers rationality. She initially dislikes Aiko Senoo due to behavioral differences but recognizes her inner goodness, bonding over shared traits. Despite Onpu Segawa's initial antagonism, Doremi remains affectionately drawn to her, playing a pivotal role in Onpu's redemption from forbidden magic use. She develops maternal devotion to Hana after witnessing her magical birth, perceived as Hana's "true mother" due to extensive caregiving. This heightens her protectiveness, sometimes leading to rash decisions, though she matures in balancing concern with responsibility over time. Her dynamic with younger sister Pop evolves from mutual antagonism—where Pop resents Doremi's immaturity—to protective pride in their sibling roles, particularly during shared witch apprenticeship trials. Classmate Tetsuya Kotake initially engages in teasing (dubbing her "Dojimi" for clumsiness), creating a contentious relationship that gradually softens into friendship, eventually developing into romantic feelings by the series' conclusion.

Character development occurs across multiple arcs. Her initial jealousy toward Pop transforms into protective pride, especially evident when undertaking witch exams that Pop cannot. Raising Hana instills profound responsibility; her sensitivity toward Hana's well-being sometimes causes interpersonal conflicts, though she learns to manage these concerns more maturely over time. Romantic inclinations shift from Akatsuki during earlier seasons to Kotake by the series finale, reflecting evolving emotional maturity. In the Ojamajo Doremi Na-i-sho OVA, an episode explores her encounter with a mysterious girl named Fami who shares similarities with her. Light novel continuations depict her as a high school student who becomes a "cool teacher," maintaining her core empathetic nature while navigating adolescence.