I went into this with very high hopes. The movie met my expectations for the first half or third of the film, but it eventually lost me.
I personally thought the rock music and modern concert elements in a time set in early Japan was a bit jarring, and kept taking me out of the film. I was left constantly thinking about how having it set in a more modern time would have made me enjoy it a lot more, at least in terms of music and believability. If you can just look past that then I think its a very good movie. I couldn't.
But other than that, I thought the characters, animation, and story were all very good. The first and last scenes especially were extremely pretty, and I loved how at the end of it all, it ties everything together. The music itself is good too. Overall enjoyed it, but it left me sad because I think it could have easily been a 10/10 movie.