At Tokise High School, the Koto club faces imminent dissolution due to a dwindling membership, leaving passionate student Takezo Kurata as its sole remaining member. The club's survival is jeopardized further by school delinquents who treat the clubroom as a hangout. Everything changes when two unexpected newcomers demand to join: Chika Kudo, a fierce delinquent with a notorious, misunderstood reputation who is actually the grandson of a revered koto maker, and Hozuki Satowa, a prodigy ostracized by the elite koto world for her rebellious streak. Although Chika initially struggles with the instrument, his profound desire to honor his late grandfather's legacy drives him to master it. Hozuki, harboring her own painful family traumas regarding her strict mother, seeks a place where she can truly express herself through music rather than mere technical perfection. Despite their clashing personalities and initial friction, Takezo steps up as a resilient leader, uniting this eccentric duo.As the narrative progresses, the club slowly attracts more troubled yet deeply talented souls. They recruit Hiro Kurusu, a girl who initially joins under false pretenses to sabotage them due to her own feelings of inadequacy, but who ultimately finds redemption and genuine friendship within the group. They also welcome three of Chika's fiercely loyal
middle school friends—Adachi, Sakai, and Mizuhara—who want to support him, alongside the easygoing yet perceptive student Mitsuya Takaoka. Together, this makeshift family transforms under Hozuki's rigorous, passionate tutelage. They are not merely learning an instrument; they are channeling their individual insecurities, past traumas, and raw emotions into a unified sound. The dramatic core of the series centers on their relentless, sweat-soaked preparation for the upcoming national koto competition.Along the way, the club faces bureaucratic hurdles, vicious rumors, and intense
psychological pressure from rival schools, most notably Hakuto High, whose polished performances highlight the Tokise club's rough edges. However, these trials only forge unbreakable bonds among the members. Romance subtly blooms, rivalries transform into mutual respect, and Chika confronts the ghosts of his past head-on. The emotional climax of their journey culminates in their breathtaking regional tournament performance of "Tenkyu," an original piece composed specifically for them. Through their soul-stirring melody, the members bare their innermost hearts to the audience and judges, proving that despite their turbulent beginnings, their synchronized chords can transcend pain and create transcendent beauty, securing their hard-fought future and establishing a legacy that resonates far beyond the walls of their high school clubroom.