An aquired taste, but a good one
I was surprised by the number of people who didn't like this movie but I can understand why. The complaints many had would apply to any number of modern Japanese soaps, which not surprisingly, are very popular in Japan.
Yes, there is overacting, sentimentality, G rated slapsticky jokes, etc. but this is part of a technique that sets the stage when playing to the modern Japanese audience. If you see where it is coming from, you can understand it better. Some of the things that might actually be realistic in Japan come off as overhanded in the west.
If you've lived in Japan (and I don't mean on a US Military base) or if you have Japanese people in your family (not Japanese American, I mean Japanese citizens), or if you are from Japan, then so much more of this movie will hit close to home than otherwise.
On another note, I notice that the director did with postwar Tokyo what Norman Rockwell did with small town America, and I think it was well done.