There is no american hegemony when it comes to Japanese food.
The only other country outside of Japan itself that you can have decent Japanese food, sushi included, is Brazil.
Japanese food in North America is actually pretty fucking trash. Especially because they have to butcher their recipes to please y’all fucked up taste preferences. Brazil you actually get the dishes very close to what they are at home with some interesting twists/fusions. Save the deep fried bullshit with cream cheeses that restaurants brought from, you guessed it, the US, fucking California to be more specific.