Hikaru Kamisaki is a central character in the figure skating story, introduced as an 11-year-old prodigy in the fifth grade. Her birthday is January 31, and her blood type is O. Orphaned at an early age, Hikaru spent her early childhood moving between the homes of distant relatives and children's welfare facilities. She was eventually taken in by the prestigious Kamisaki family, who had ties to her grandfather. This family heavily valued tradition and frequently scolded her for etiquette mistakes, leading Hikaru to run away and return with bruises and scratches, taking refuge with the elderly family head who would play with her. Recognizing her impulsiveness and rare athletic ability, the family head suggested she channel her energy into sports and gifted her a gold pendant as a victory charm, which she cherishes deeply.

Publicly, Hikaru belongs to the Meiko Wind Figure Skating Club in Nagoya, run by former Olympic silver medalist Shinichiro Sonidori. In secret, her real coach is former Olympic gold medalist Jun Yodaka, a fact so well-hidden that even her fellow club members are unaware. Hikaru boards at the Sonidori family home, living together with Shinichiro’s son, Rioh Sonidori, who is both her teammate and childhood friend. She is taken care of by Rioh's mother, Eva, and considers the Sonidoris her adoptive family, though she initially struggled to accept this due to her complicated past.

Hikaru’s personality is friendly, sociable, and surprisingly considerate for someone with such overwhelming talent. She does not come off as arrogant or cruel and responds warmly to people who treat her like a normal girl rather than a celebrity, which is why she takes an immediate liking to the protagonist, Inori Yuitsuka, who first reacts to her as simply a girl in a princess dress. Despite this outward warmth, her existence as an extreme prodigy isolates her. Many skaters her age admire her from afar or see her as an unreachable rival, and her overwhelming level once caused several members to leave her club because they felt they could not match her talent. She is extremely strict with herself when it comes to skating, embodying Jun Yodaka's philosophy that sacrifice is indispensable for victory, and she does not hesitate to face harsh training and sacrifices for success.

Hikaru’s primary motivation is her rivalry with Inori Yuitsuka, whom she met by chance and promised to compete against on the national stage. She also seeks to understand and eventually surpass her coach, Jun Yodaka, viewing her skating career as a medalist path to challenge him. Her role in the story is that of the main rival to the protagonist, representing the pinnacle of skill that Inori aspires to reach. Known as the center of the Kamisaki generation, her dominance raises the overall level of young skaters in Japan. Her key relationships include Rioh Sonidori, who is devoted to her and acts as her emotional anchor, though Hikaru largely ignores any romantic implications and sees him as family. Her relationship with Jun is complex; while he is her mentor and the reason she skates, she eventually decides to transfer to a new club in Tokyo to better understand him and develop her own abilities, leading to a temporary falling out.

Notable abilities are at the core of Hikaru's character. By the fifth grade, she can successfully land all six standard triple jumps, including the notoriously difficult triple Axel, and execute triple-triple combinations like a triple Lutz followed immediately by a triple loop. Her skating skills, including edge control, body alignment, and flow, are considered far beyond the level of a novice skater. Her on-ice presence is described as overwhelming and regal, making audiences feel as though an absolute queen is burning her life away on the ice. She later performs even more difficult elements, including a quadruple toe loop in competition. Hikaru has never lost a competition by the time she appears in the story, winning gold at every event she enters.