Yumi Hanazono is a young girl distinguished by her long auburn hair, blue eyes, and freckles, typically styled in a braided ponytail secured by a large yellow bow. Her standard outfit features a pink skirt, a red vest layered over a white puffy-sleeved shirt, and red shoes with white socks.

Raised in her family's flower shop, Yumi possesses a deep appreciation for flowers cultivated from childhood. Though she struggles academically, she exhibits exceptional artistic talent and dreams of becoming a manga artist. Her personality blends a spunky, active imagination with tomboyish tendencies; she prefers playing sports and outdoor activities with boys, sometimes causing social friction with girls who criticize her as "unwomanly." These critiques occasionally prompt her to attempt more traditionally girly behaviors.

Yumi's magical abilities stem from two flower fairies, Kakimaru and Keshimaru, who gift her a wand and pendant after witnessing her kindness towards flowers. By drawing in the air with her wand and reciting "Pastel Poppuru Poppin-pa!", she materializes any imagined object, creature, being, or magical item, including inanimate objects, living entities, clones of existing individuals, and devices like winged boots or memory-altering tools. Her creations disintegrate into flower petals after a temporary duration, signaled by a flashing pendant. Key limitations prevent summoning the same thing twice and restrict concurrent summons, though enforcement varies. Manifestation durations range from seconds to an entire day.

A significant story arc sees Yumi lose her magical powers when the Land of Flowers falls into crisis, causing unnatural events like summer snowfall. Traveling to this realm, she discovers the queen asleep, leading to withered flowers and giant insect infestations. Tasked with retrieving "silver drops" from a distant mountain to awaken the queen, she faces sabotage by a rival. In the climax, she temporarily regains her magic to create wings, flies past attacking insects, and successfully revives the queen. After restoring the land, she returns home as the flower fairies remain in their realm, bidding her farewell.

In the crossover OVA "Majokko Club Yoningumi: A Kūkan Kara no Alien X," Yumi collaborates with other magical girls against an extraterrestrial threat, using her drawing ability to create functional spacesuits for the team.

Yumi stands out as the only magical girl in Studio Pierrot's lineup without transformation abilities, possessing no alternate identity or secret life. Her character development consistently centers on balancing her authentic self with social expectations, leveraging creativity to solve problems, and navigating the responsibilities and limitations of her powers.