As for many submarine kind of movies, you have to know what you are getting into to enjoy it (a.k.a anxiety and frustration).
I found that the actors played very well, in a subtle manner, which makes the movie closer to actually depicting reality. I really liked that the end is not a Hollywood happy end.
A dive into Japanese culture, where family matters a great deal. Very moving, quite aesthetic images.
The great plot twist at the end is thought-provoking, it totally got me.
Great movie! It's a perfect illustration of how people, though very different from one another, can learn from each other. Very funny too. It's a movie that gives hope!