Shouya Ishida, a mischievous elementary schooler, found entertainment in cruel antics until a new student, Shouko Nishimiya, who is deaf, joins their class. Engaging in thoughtless bullying with his peers, Shouya faces the consequences when he becomes the scapegoat for their actions. As Shouko transfers out due to the harassment, Shouya bears the weight of isolation and scorn from his classmates, enduring a lonely journey through elementary and middle school. In his final year of high school, burdened by remorse from his youth, Shouya seeks redemption by reuniting with Shouko to seek forgiveness. 'Koe no Katachi' follows Shouya's heartfelt quest to make amends with Shouko, grappling with the lingering ghosts of his past deeds.