In the based-on-a-true-story book 'In Cold Blood,' by Truman Capote, there is mention of Japanese family living in Kansas in 1959. During WWII, many Japanese Americans were interned, sure, but were all of them?
Not all Japanese-Americans were interned, there was an exclusion area along the West coast through Washington, Oregon, California, and Arizona where Japanese-Americans were removed from and sent to internment camps. Japanese-Americans outside those areas, including those living in Hawaii, were allowed to continue doing so. Notable Japanese-Americans were interned along with everyone else.
The only Japanese dignitaries I'm aware of who were in the US at the time were the 2 ambassadors, who were imprisoned after the outbreak of war and held until an exchange for US diplomats that were in Japan that happened in 1942.
As far as I'm aware, all persons of Japanese ancestry in the exclusion zones (whether US citizens or visitors from Japan) were interned.