Haruka Nanase, called "Haru," is a competitive swimmer intrinsically bound to water. Originating in Iwatobi, he formed an early, profound connection with water, considering it his true element. For Haru, swimming, especially freestyle, represents freedom and self-expression, transcending mere sport. He believes water enables communication and makes him feel genuinely alive. A middle school incident involving Rin Matsuoka prompted Haru to quit competitive swimming temporarily. He resumed in high school after reconciling with Rin and joining the Iwatobi High School Swim Club. His deep bond with childhood friend Makoto Tachibana is central; Makoto frequently acts as his communicator and caretaker, while Haru instinctively protects Makoto, particularly from his fear of the ocean. Their relationship endures conflicts, such as a disagreement over Makoto's choice to study in Tokyo, which caused a temporary rift but ultimately solidified their connection. Haru's personality is introverted and reserved, often identified as ISTP (Myers-Briggs) and Enneagram Type 9w8. He exhibits high-functioning autistic traits, experiencing difficulty processing emotions and social cues, though he does not formally recognize these as neuroses. He communicates minimally, relying on subtle body language and actions, yet demonstrates sarcasm and bluntness. His assertiveness is conveyed through his consistent use of the pronoun "ore." A pivotal regional competition shattered him. Overwhelmed by external pressure from scouts, peers, and expectations of his "prodigy" status, he suffered a mental breakdown, stopping mid-race. The pressure reduced swimming to a mechanical task, stripping away his sense of freedom and joy. This forced him and others to confront the necessity of swimming retaining personal meaning beyond titles or external validation. Post-high school, Haru attended university in Tokyo on a sports scholarship. He adapted to urban life, utilizing apps for navigation and studying nutrition to enhance his swimming. His focus remains water-centric, with daily rituals including two baths for meditation and mood regulation. He maintains tidy living spaces and prefers simple, comfortable clothing in blues and purples. His diet centers on mackerel, incorporated into most meals. His swimming career intensified as he targeted international competitions. Rigorous training sometimes pushed him to physical collapse, resulting in hospitalization during a tournament. This led to a temporary retirement, though he returned after rehabilitation. His rivalry with Albert Volandel evolved into mutual respect, culminating in a relay race victory for Haru's team. Despite setbacks, he continued competing, eventually participating in events in Hungary and Japan. Haru's development involved reconciling past relationships, such as reconnecting with Ikuya Kirishima after years of estrangement. He learned to balance his solitary passion for swimming with the support of friends, recognizing that shared goals and camaraderie enhance his connection to water. His journey concluded with a reaffirmed commitment to swimming, accepting his path might diverge from conventional adulthood but remains true to his identity.