Haruka Nanase, a male university student with black hair, blue eyes, and a muscular 177 cm frame, carries a name rooted in themes of distance, spring, clarity, and floral imagery. His lifelong affinity for water began in childhood, frequently wearing swimwear beneath his clothes for impromptu dips. A formative bond with Makoto Tachibana emerged in elementary school after Haruka aided him during a playground fall, cementing Makoto as his social anchor. In elementary school, Haruka joined the Iwatobi Swimming Club with Makoto, Nagisa Hazuki, and Rin Matsuoka, their relay team clinching a tournament victory. A private race loss spurred Rin to quit swimming, leaving Haruka guilt-ridden and abandoning competition until high school. A chance rematch with Rin reignited their rivalry, driving Haruka to co-found the Iwatobi High Swim Club as vice-captain. His freestyle prowess, characterized by fluid, instinctive movements emphasizing unity with water, inspired teammates. Haruka’s high school years brought turmoil as scouting demands and the label of a "swimming machine" overwhelmed him, culminating in a breakdown. A Sydney trip and friends’ encouragement restored his resolve, leading him to pursue swimming professionally at Hidaka University. There, he reconnected with Ikuya Kirishima, a former junior high teammate resentful over their past team’s disbandment. To reconcile, Haruka mastered multiple strokes, competing alongside Ikuya in an Individual Medley—a shift from solitary focus to collaborative growth. His career peaked with gold medals in global medley relays as a Japan National Team member. Orphaned of parental presence after his grandmother’s passing, Haruka lived independently, his parents employed in Hokkaido. Stoic yet quietly protective, he shielded Makoto from drowning and emotional strain. His rivalry with Rin matured into mutual respect, fueled by shared dedication to friendship and self-improvement. Notable quirks include a mackerel obsession, artistic flair in drawing and woodcarving, and a penchant for swimming in unlikely locales, underscoring his unyielding bond with water.