If you want happy and cute and cheerful, then this movie is not for you. If you want pain and heartache, but also love and friendship and guilt and redemption, then watch it. The characters are complex, the story is compelling, and the emotions are very real. There are some issues with the way the film deals with deafness (see below), but overall it's still a fantastic film. 10/10.
The good (bullying):
Some viewers may think that Shouko is an unrealistic character -- she's just too sweet and kind. Given everything that Shouya did to her, how could she possibly forgive him? Why doesn't she hate him? Having experienced bullying myself, though, I really identified with Shouko, and I thought her character was spot on.
The thing is, victims of bullying often blame themselves, rather than blaming the bullies. After all, why are bullies picking on you? It's because you're different, because you don't fit in. That's clearly how Shouko feels, because she's constantly apologizing. She blames herself.
Consequently, if a bully later turns around and starts acting nice, it's not hard to forgive them. In fact, the emotion can easily run in the opposite direction -- it feels as though the bully has finally forgiven you for being different, and has accepted you as a person.
Again, I can speak from personal experience. There was this guy who always bullied me in middle school, but I didn't hate him, I just tried to avoid him. Then in high school, he grew up. There was an incident in which someone else was picking on me, and he actually came to my defense. That was a big deal to me. We didn't become friends or anything, but I really respected him after that for turning things around.
The bad (deafness):
I think the main problem with this movie is the way it deals with the deaf community, or lack thereof. Why was Shouko enrolled in a hearing school at all? I am not an expert on the deaf community, but my understanding is that it is standard practice to enroll deaf children in special schools for the deaf. Putting a deaf child in a school where they can't understand the language, and never will, is practically child abuse.
Similarly, when Shouko is in high school, where are her deaf friends? The deaf community is very tightly-knit, and in any large city, there should be a sizeable group of deaf peers for Shouko to interact with. Shouko knows sign language, so she must have had instruction from a tutor. She didn't learn it from her hearing mother, and her tutor should have been well-connected with the deaf community.
Failing that, why didn't she make any new hearing friends at her new school? We see that even in high school, Shouko is still socially isolated, and dependent on her sister for almost all social interaction. That setup is necessary for the plot, but it doesn't feel realistic to me.
Conclusion:
If you accept the premise of the movie -- that Shouko somehow lives in a place (maybe small town?) where there are no other deaf people -- then this is a fantastic movie. If you want a guide to what the lives of deaf people are actually like, not so much.
