I am from Brazil and I know some people that are mixed japaneses. It seems that the niponic genes tend to overcome the western ones =P
In this article in Wikipedia you can see that the japanese brazilians aren't any different from the ones in Japan.
Japanese Brazilian - Wikipedia, the free encyclopedia
I believe that the diet is the cause of some corporal small differences, like the size of the breasts, height and so on.
Just to note: I am mixed of portuguese, german and amerindian... xD