Shirayuki Hime, originally known as Himelda Window Cure Queen of the Blue Sky, hails from the Blue Sky Kingdom after its conquest by the Phantom Empire. Forced to flee to Earth, she lived at Pikarigaoka's embassy under Blue, Earth's guardian deity. Initially appointed as a Pretty Cure to defend her homeland, her severe timidity and anxiety rendered her ineffective in battle against Saiark monsters, requiring frequent rescues by allies like Cure Fortune—who openly criticized her perceived weaknesses.

Her turning point came when Blue gave her a Love Crystal to choose a partner. She threw it from a building, unintentionally striking Aino Megumi, a cheerful middle schooler. Witnessing Megumi instinctively shield her from a Saiark activated Megumi's transformation into Cure Lovely, sparking their partnership and the HappinessCharge Pretty Cure team. This marked Hime's first true friendship and the start of her emotional growth. As Cure Princess, she wields a transformation mirror and PreCards for form changes and specialized attacks, primarily manipulating wind with techniques like Princess Tornado. Alternate battle forms include Sherbet Ballet (ice and ballet-inspired maneuvers), Macadamia Hula Dance (nature-themed hula), and an advanced Innocent Form resembling an idol outfit, activated when protecting loved ones.

Hime embodies a spoiled fashionista with sharp style instincts, though her initial selfishness sometimes surfaces—like prioritizing hunger over team duties. Debilitating shyness once caused her to faint during social interactions, but her bond with Megumi, rooted in shared fashion passion, gradually built her confidence. She formed friendships like that with Omori Yuko (Cure Honey), who soothed her with homemade honey candy. A major rift occurred with Hikawa Iona (Cure Fortune), who blamed Hime for unwittingly freeing the Phantom Empire by opening the Axia artifact, deceived by a voice within it. Despite Iona's hostility, Hime surrendered her PreCards—meant for restoring her kingdom—to fulfill Iona's wish of reviving her sister. Their reconciliation during a joint shopping trip and battle evolved into a sisterly dynamic, with Iona becoming protective.

Hime experienced fleeting romantic interests: a crush on Sagara Seiji after his assistance, mistaking gratitude for affection, which faded upon recognizing Megumi's deeper bond with him. In "The Ballerina of the Land of Dolls," she briefly admired Prince Zeke of the Doll Kingdom, unaware he was a sentient doll created by Phantom Empire puppet Tsumugi. Witnessing Zeke's sacrifice for the Cures revealed the superficiality of her feelings, cementing her focus on friendship.

Her relationship with fairy companion Ribbon resembles family, with Ribbon as a strict caretaker who scolds her over diet and health, leading to playful bickering. Mentor Blue maintains a supportive, sibling-like rapport. Hime's development centers on evolving from a cowardly fighter reliant on others to a determined Cure capable of teamwork. Her social anxiety diminished, allowing lasting bonds and acceptance of her dual role as princess and warrior. Core motivations include atoning for freeing the Phantom Empire and restoring the Blue Sky Kingdom—a goal she prioritizes over personal wishes despite opportunities to use PreCards otherwise. Her name "Shirayuki Hime" (Snow White Princess) reflects her royal lineage and fairy tale narrative role.