Kota Mizuhara, a first-year student at Tokise High School, actively participates in the school's koto club. He possesses light blonde hair, large round eyes, and an average height of 170 cm at the story's start, with potential for future growth. Kota frequently modifies the school uniform, typically wearing the regulation checkered brown pants but pairing them with colored hoodies over his shirt, non-regulation shoes, and a personal backpack instead of the standard bag. He only adheres strictly to the full uniform during koto club performances. Exhibiting a cheerful and sensitive personality, Kota often displays childlike enthusiasm. He habitually expresses affection through physical hugs towards people he likes, conveying friendly warmth without deeper meaning. Despite his generally easygoing nature, he possesses a complete lack of rhythm sense. Kota shares close, long-standing friendships with fellow koto club members Chika Kudo, Saneyasu Adachi, and Michitaka Sakai, dating back to middle school. Together with Adachi and Sakai, he forms the trio informally known as the "Three Idiots," reflecting their deep camaraderie since kindergarten. Raised alongside three older sisters who actively spoil and adore him – one an office worker, another a dentist, and the third working at a fitness club front desk – this familial environment likely influences his affectionate demeanor. Kota personally favors spicy food intensely, especially habanero peppers, while disliking raw fish. He joined the koto club alongside Chika and his other longtime friends during efforts to recruit members and prevent the club's disbandment. His consistent presence as part of the ensemble underscores his dedication. Like all core club members, Kota participates in rigorous practice sessions and performances, contributing to the group's collective growth and shared goal of reaching the national koto competition.