Takeuchi-sensei was the homeroom teacher of Shouya, Shouko, Naoka, Shimada, Hirose, Miki, and Miyoko during their 6th-grade year.

~!While he was disappointed in Ishida for bullying Nishimiya, he still laughed at the jokes made about her, and once Nishimiya left, he prompted the class to turn Ishida into a scapegoat for all their bullying. He refused to believe Ishida when he claimed he was being bullied too. Years later, Ishida runs into Takeuchi again when looking for locations for the film. Takeuchi says that Ishida has grown into a fine young man and all the bad things in his past have changed Ishida for the better. Mashiba dislikes how Takeuchi talks about Nishimiya and throws his drink into Takeuchi's face, costing them the chance to film at the school, though with Ishida's later hospitalization and Mashiba's apology to him, Takeuchi allows them to shoot anyway.!~

After transferring into a new school, a deaf girl, Shouko Nishimiya, is bullied by the popular Shouya Ishida. As Shouya continues to bully Shouko, the class turns its back on him. Shouko transfers and Shouya grows up as an outcast. Alone and depressed, the regretful Shouya finds Shouko to make amends.
 
(Source: Eleven Arts)

[Synchronkartei](https://www.synchronkartei.de/sprecher/428/2)

Based on a one-shot that won the 80th Weekly Shounen Magazine Newbie Best Mangaka Award. 
Shouya is a bully. When Shouko, a girl who can't hear, enters his elementary school class, she becomes their favorite target, and Shouya and his friends goad each other into devising new tortures for her. But the children's cruelty goes too far. Shouko is forced to leave the school, and Shouya ends up shouldering all the blame. Six years later, the two meet again. Can Shouya make up for his past mistakes, or is it too late? 
(Source: Kodansha USA) 
Note: Includes 2 extra chapters.