Haruka Haruno comes from the family running the Japanese sweets shop "Haruya". Her princess dream sparked in kindergarten when classmates bullied her for it, until Prince Kanata encouraged her to hold onto that dream. He gifted her a charm that later became her Dress Up Key, cementing her resolve. She enrolls at Noble Academy as a first-year student, distinguished by thick eyebrows and a flower clip in her curly auburn hair. Her civilian outfits favor floral dresses, like a pink-check dress with a white collar or seasonal variations such as a pale-yellow sweater with pink details. Energetically determined yet notably clumsy, she struggles academically but masters skills like ballet or violin rapidly when focused. Her speech bursts with "Suteki sugiru!" ("Too amazing!") and declarations of things being "mankai" ("in full bloom").

With the phrase "Pretty Cure Princess Engage!", she uses her Dress Up Key and Princess Perfume to transform into Cure Flora, the Princess of Flowers. Her hair lengthens into a blonde-and-rosy ombre cascade, crowned by a gold flower tiara. The costume layers pink skirts with floral accents, pairs white gloves adorned with pink flowers, and features bow-detailed shoes. Her Floral Tourbillon attack unleashes petal storms, while Mode Elegant variations alter aesthetics and elements: Rose Tourbillon swirls red rose petals, Lys Tourbillon white lilies, and Sakura Turbulence cherry blossoms. Mode Elegant Halloween introduces orange floral details and a chiffon dress.

During movie events, she teleports from a cafe to the Pumpkin Kingdom’s Princess Convention. There, she aids captive Princess Pumplulu by preparing her family’s special pudding, restoring the memories of the brainwashed king and queen. This unites the kingdom’s dreams, creating Halloween Dress Up Keys to empower the Cures against antagonist Warp. Later, she helps Princess Leff restore light to her kingdom by confronting Night Pumpkin, utilizing the Halloween Eclair attack and appearing in Grand Princess form—a gold-ombre ballgown with a flowing cape.

Her enduring bond with Prince Kanata anchors her childhood inspiration. She fiercely defends roommate Yui Nanase from antagonists and admires Minami Kaido’s elegance and intellect. Kirara Amanogawa nicknames her "HaruHaru", sharing a playful dynamic. Her relationship with Towa Akagi evolves from hostility to mutual respect after reigniting Towa’s belief in dreams. She confronts childhood bully Yuuki Aihara at the academy, gradually resolving past tensions. Antagonist Close specifically targets her dreams to incite despair, fueling their clashes.

Temporary depowerment strikes when Kanata’s admonition to abandon her "impossible" dream plunges her into despair, stripping transformation abilities. Encouragement from friends restores her resilience. She later achieves Grand Princess Mode, symbolizing growth into a "true princess". Her final battle against Close ends by persuading him that dreams coexist with despair, prompting his peaceful departure.

As an adult, she keeps a crystal replica of her Dress Up Key and revisits the flower field where she first met Kanata. Longer hair and attire echoing her original clothing reflect her realized princess aspirations through dedication. Thematically, "Haruno" blends "spring" and "field", while "Haruka" means "spring flower" or "distant"—mirroring her floral motif and journey. The title Cure Flora draws from Roman mythology’s flower goddess and botanical terms, aligning with her identity as the Princess of Flowers.