You'd think advanced knowledge of Japanese culture is a requirement at Marvel considering how many Japanese-themed storylines they enjoy pulling lately, but apparently it's more like "remotely passable knowledge (ex. know the words karate and daimyo--you don't necessarily have to know what it means!)." And you're right, he definitely looks Native American and not remotely Asian. I guess Deadpool calls him Eurotrash once and everyone forgets he's not remotely from Europe.