They are most populous in Brazil. The country of Brazil boasts to have the largest population of Japanese born outside of Japan than anywhere else on earth. Their overall population there has just exceeded more than one million. Here is a really good video clip about it [yt=Brazillian Japanese]P7j6N5-Ajl0[/yt]
It can boast all it wants, but America has more than 1.2M just of Japanese (who are only the 6th largest Asian American population in the US), so....