I'm sorry, but even for kids what all of those people were doing was just too cruel. Maybe if all they were doing was ignoring her I could forgive them in the end, but they went too far. They were beating her, pushing her into puddles, mocking her LITERALLY TO HER FACE, and destroying her SUPER EXPENSIVE equipment. It's just wrong. Frankly, all of those people should just go die because the world would be a MUCH BETTER PLACE without people like them. Even the MC who became nice in the end AND tried to own up to his wrongs at the time doesn't deserve forgiveness since he was the worst while she was still protecting his feelings. In fact, the deaf girl deserves acceptance into sainthood for all they did while the rest of her classmates simply deserved a very early death!
Seriously, mangas like this do nothing but enrage me because they act like people can be forgiven for anything if they just say sorry, but, frankly, that shouldn't be the case. If that was the case, we wouldn't need the death penalty or prison. Actually, if those kids weren't minors they could have been facing jail-time (in America, at least) or, at the very least, fines so large that their lives would, deservingly, be ruined for a good amount of time.