Japan considered overseas Japanese citizens of Japan, regardless of the citizenship status of their birth or overseas citizenship, based on ethnicity only:
Shoal of Time, a History of Hawaii
Some US-Japanese citizens spied for Japan prior to the Pearl Harbor attack.

See also Permanent Resident Alien vs. Enemy Alien

I detest these kind of equivalencies, another “Oh how horrible we are” scenario. Racism was not unique to the USA or Japan, either then or now. Go to japan, as I have (I love the country and people, and can speak and read passable Japanese) and you’ll quickly find out what a “Gaijin” is, especially if you try to get a drink in a bar and get turned out “Japanese only, no gaijin”

Reading was suggested for us, well I’ve got one too.
War without Mercy :Race and Power in the Pacific War
You’ll find racism was not confined to the USA. You might ask some Koreans about it also concerning Japanese attitudes toward them, try “comfort women”.

I concur with Render, ploome and J.S, Any equivalencies to the treatment of Jews in Europe is contemptible.