Yuna Kamihara lives with her grandmother on Izayoi Island after her mother’s death in an infancy typhoon. Her marine biologist father maintains a loving yet distant relationship due to work absences. Physically small and fair-skinned, she sports brown hair in spiky ponytails—initially with blue beads, later green scrunchies. She typically wears a red sleeveless dress patterned with yellow flowers. Early seasons show her in light blue-striped sweatpants and heart-motif pink sandals, evolving to rolled blue jeans and orange sneakers with white soles in later years. Additional outfits include a pink nightgown, red bathing suit, and a white karategi with black belt for martial arts. Her personality blends kindness and politeness with fierce protectiveness and tomboyishness. She reacts intensely to injustice or bullying, often interceding defensively with her karate skills—a black belt who inherited her island’s dojo from her grandfather. Though playful and competitive with friends like Stitch, pressure can escalate this trait. She harbors a fear of thunderstorms, countering it by rubbing her belly button for luck, highlighting Stitch’s lack of one. Academically, she struggles profoundly with mathematics, frequently scoring poorly. While usually internalizing distress to avoid burdening others, overwhelming stress triggers angry outbursts or tearful collapses, mitigated by support from friends, especially Stitch. Her life shifts when she encounters Stitch, an extraterrestrial; their initial clash becomes a deep bond sealed by a pinky swear. As Stitch’s primary caretaker, she introduces him to human customs, Okinawan culture, and karate, expanding her circle to include Jumba, Pleakley, Stitch’s "cousin" experiments, and local yokai like Kijimunaa. Her cousin Tigerlily Sakai moves in during the second season, initially bullying Yuna into chores via blackmail while charming others. Tigerlily later transitions to a caretaker role. Yuna also maintains a persistent rivalry with Penny, a wealthy island resident whose mockery sparks physical clashes. They occasionally collaborate uneasily, but antagonism endures even after Yuna relocates. Across the series, she ages from 10 to 12–13, celebrating her 11th birthday early on. She moves from Izayoi Island to Okinawa New Town with Stitch, Tigerlily, Jumba, and Pleakley, adapting to urban life, a new school, and fresh rivalries like classmate Jessica. Tigerlily softens during this period, fostering support. Yuna gradually matures emotionally while retaining core traits: protectiveness, competitiveness, and reliance on karate. Notable possessions include a moonsand charm from her grandfather for karate luck. Remmy, an experiment, once showed her a vision of her deceased mother humming "Baby Mine" from *Dumbo*. Her full name, 上原ユウナ (Kamihara Yūna), uses Okinawan pronunciation for the surname kanji meaning "upper plain."