Haruka Haruno is a 13-year-old first-year middle school student attending the prestigious Noble Academy, having transferred there with the goal of pursuing her dreams. She is a cheerful, energetic, and optimistic girl who possesses a relentless spirit and an unyielding commitment to achieving her aspirations, though she sometimes displays a tendency toward clumsiness or impulsiveness. Her defining characteristic is her profound passion for becoming a princess, a dream that was born from loving picture books like The Princess of Flowers during childhood and solidified through her love for flowers and gardening. However, she has a degree of shyness about openly sharing this ambition, as her dream was once made fun of by a classmate when she was younger. Despite this vulnerability, she is not easily brought down and will always stand up for her beliefs, putting in all the required work and then some to achieve her goals.

Haruka’s core motivation is the belief that a true princess embodies kindness, grace, and the power to fulfill dreams through perseverance and noble character, not simply through status or appearance. Her life transforms when she is chosen to become a Pretty Cure, a guardian tasked with protecting the Hope Kingdom from forces of despair. As Cure Flora, the Princess of Flourishing Flowers, her catchphrase is "Doki Doki!" which expresses her excitement and determination. In the story of "Eiga Precure All Stars: Haru no Carnival," Haruka and her friends Minami and Kirara are invited to the kingdom of Harmonia, a country of dance and song, to participate in a spring carnival alongside many other Pretty Cure warriors. There, she faces her personal struggle with stage fright and the fear of singing in front of a crowd, which becomes a central challenge. When the carnival is thrown into chaos by the announcers Odoren and Utaen, who steal the fairies and the Cures' transformation devices, Haruka is faced with a moment of despair. Instead of succumbing to it, she fights back through song and dance, conquering her fear and inspiring the revival of everyone's powers.

Haruka forms deep and pivotal bonds with her fellow Pretty Cure warriors and roommates at Noble Academy. She initially looked up to Minami Kaido, also known as Cure Mermaid, with a sense of intimidation, seeing her as a perfect and elegant figure, but through training and shared experiences, they become close, reliable friends. With Kirara Amanogawa, Cure Twinkle, Haruka shares a bond of mutual admiration and support, with Kirara affectionately nicknaming her "Haru Haru". Her initial transformation into Cure Flora was driven by her desire to save her first friend at the academy, Yui Nanase, whose dream was being threatened. Prince Kanata from the Hope Kingdom is also a significant figure in her life, as he was one of the first people to encourage her dream and gave her the Dress-Up Key that enables her transformation.

Throughout her journey, which includes the events of "Haru no Carnival," Haruka undergoes notable development. She learns that being a true princess comes from inner fortitude, resilience, and the ability to inspire others, not from external validation. Her key development in the film is overcoming her intense stage fright, using the power of music and dance—which she learns from the senior Pretty Cure warriors—not only to save herself but to help unite all the Cures in creating a miracle to calm an angry guardian dragon and restore peace to Harmonia. As Cure Flora, her notable abilities are floral-themed and tied to her Princess Perfume and Dress-Up Keys. Her signature attacks include the Precure Floral Tourbillon, a spinning vortex of flower petals, and the Precure Flora Reflection, a shield of light and flowers. In "Haru no Carnival," she and her team also gain the ability to use Mode Elegant and the combined attack Rainbow Tornado to appease the deity of Harmonia.