Kōta Mizuhara is a second-year student at Tokise High School and a member of its koto club. He shares a past history of delinquent activities with fellow club members Saneyasu Adachi and Michitaka Sakai. Academically, Kōta struggles with traditional studies, finding more effective learning through practical experience and an emotional connection to music rather than theoretical lessons. Within the diverse koto club, he contributes to the ensemble's dynamic; despite initial appearances of being mismatched or inexperienced, the group unites through rigorous practice to pursue shared goals. His participation in the club marks a distinct shift away from his earlier delinquent lifestyle towards a dedicated focus on the koto, demonstrating personal growth fostered by commitment to the instrument and the group's camaraderie.