I truly don't get the hype about that movie. They definitely got the visuals right, but a lot of it felt "off". Quite a few of the cultural stereotypes were awkwardly over-played too.
Also, Japan is really a different bird when it comes to integration. Not all countries have the same jarring and visceral division between foreigners and local society.
Don't get me wrong, the international community is very accepting, even loving. But when you get to actual nationals, other than a few exceptions, you'll never be truly accepted.
I lived there for a few years as a teenager, and didn't really have an experience that jived with the general atmosphere depicted in the movie. YMMV, I suppose.
On the overplaying the foreignness people on their first sojourn in a really foreign country do the tourist goggling all the time. One needs a lot of foreign travel experience to start treating it as just some more different shit.