Japan is notably more xenophobic. No matter how long you live in Japan, even if you manage to get full citizenship (which even celebrities who have lived there for decades struggle with), you are never considered "Japanese" by the native-born Japanese people.
The USA on the other hand is comparatively easy to become a citizen of and has laws banning discrimination based on race and national origin for employers. A citizen is a citizen is a citizen. The only job in the entire country that requires you be born as a citizen is the POTUS.