Years ago, Shoya Ishida led his peers in tormenting a hearing-impaired classmate, Shoko Nishimiya. When she transfers schools, Shoya finds he has gone from bully to bullied, and is left completely alone. Now Shoya struggles to redeem himself in Shoko's eyes and to face the classmates who turned on him.

He learns sign language to apologise to Shoko for his behaviour, and so begins a relationship that will change his and Shoko's lives forever.

Despite their tense pasts, Shoya begins to embrace the friend group that used to terrorize Shoko because she couldn’t hear. Now that summer vacation is in full swing, the crew can work together to film Tomohiro’s eccentric movie. Each fun-filled day lazily passes by, but doubt tugs at Shoya’s heavy heart and he is desperate to cling on to meaningful moments before they are gone…