Go buy the book in my post just above yours.
There were a bunch of Japanese-heritage fisherman operating out of an island near LA and Long Beach harbors who were sending in intelligence, for one example.
The Japanese of that era were sending their kids back to Japan for primary education. So a lot of them were really more culturally Japanese than American. I want to take nothing away from the Nisei battalion or regiment that fought in the European Theater, who were very highly decorated, even as their families were often interned. But there were also those working for the Japanese. It was a tough call in an existential war.