Doremi Harukaze is the main protagonist of the story, an elementary school girl who lives in the city of Misora and attends the First Elementary School. She is known for her distinctive appearance, which includes long red hair styled into two large buns held by pink scrunchies, one of which is decorated with a yellow music note, along with mulberry-colored eyes. Her birthday is July 30, she has blood type B, and her favorite color is pink.

Doremi often proclaims herself to be the unluckiest pretty girl in the world, a reflection of her genuine clumsiness and tendency to experience small misfortunes. Despite this self-assessment, her core personality is lively, kind-hearted, and fiercely compassionate. She is energetic and outgoing, and while she can sometimes be selfish or act impulsively, she is driven by a persistent desire to care for the people around her, often meddling in their troubles. Her ongoing struggle with academics and her occasional lack of focus are contrasted by her optimistic nature and refusal to hold grudges.

Several defining experiences shape her background and motivations. A childhood trauma from forgetting her piano piece during a recital has given her complicated feelings about the instrument she still loves. This event is directly linked to her obsession with steak, which became her favorite food as a way to cheer herself up afterward, though her hopes of actually getting to enjoy a full steak often end in comedic failure. Her initial desire to become a witch was motivated by a wish to gain the courage to confess her feelings to a boy she liked, though she eventually learns that such things can be achieved without magic.

In the final season, Ojamajo Doremi DOKKAAN!, Doremi faces her most significant challenges. The magical infant Hana, whom Doremi has helped care for since her birth, uses her power to age herself up to match the age of the group, which shatters her own magical crystals and strains their resources. Doremi and her fellow apprentices must work to replenish Hana's energy while confronting a powerful curse that threatens both the human and witch worlds by spreading apathy. Throughout this arc, Doremi's growth is evident as she moves beyond her earlier childish frustrations. When faced with the offer to become a full-fledged witch, which would grant her unnaturally long life, she leads her friends in the difficult decision to renounce their magic and remain human, reaffirming her faith in ordinary solutions and human bonds over power.

Her key relationships are central to her development. She shares an unwavering camaraderie with Hazuki Fujiwara, a childhood friend since kindergarten, and a deep, sometimes rivalrous friendship with Aiko Senoo. She also develops a strong alliance with Onpu Segawa, which begins as a rivalry when Onpu uses forbidden magic but transforms into a deep friendship after Doremi's genuine concern helps save her. Her relationship with her younger sister, Pop, evolves from typical sibling jealousy and rivalry into a mature, respectful bond with Doremi taking great pride in being the older sister. Her role as the primary caregiver for the magical baby Hana also fosters strong maternal instincts, forcing her to balance overprotectiveness with trust and responsibility. Simultaneously, her feelings for her classmate Tetsuya Kotake grow from mutual antagonism into a genuine romance, forming a significant part of her personal journey.

As a witch apprentice, Doremi uses a pink Magic Sphere and casts spells with the incantation Pirika Pirilala Poporina Peperuto. Her magical theme color is pink, and she has a fairy companion named Dodo. Her spells often misfire due to distraction, hunger, or emotional states, particularly in the early parts of her training. However, through persistent practice and the support of her friends, she gradually hones her magical control and becomes a capable, if still occasionally clumsy, witch.