This is truly an incredible film. I'm not one to cry while watching movies, but I've seen A Silent Voice three times now and get emotional every time. It's a simple story but one that carries so much weight in its themes and messages--the kind of movie everybody should watch at least once.
I've seen some complaints that the main character is too unlikable to be a protagonist, but I couldn't disagree more. Shoya is a deeply troubled young man who seeks to make amends with the girl he used to torment, and though he makes mistakes, that's what makes him so realistic. We've all done things we regret; the true test of character is the way we handle those mistakes. I loved watching his growth throughout the movie, and while I liked Shouko and the other characters, I found Shoya to be the most compelling.
This movie also handles darker themes like self-loathing and suicide very well, ultimately giving a message of hope that we so desperately need in this day and age. As a bonus, not only is the story of A Silent Voice amazing, but the art and animation are gorgeous and create a very distinct atmosphere that matches the somber theme and story very well.
In conclusion, A Silent Voice is a beautiful, emotional masterpiece in a way that's unlike any other movie I've seen. It's 100% worth the watch.