-—The Japanese of WWII were very racist.-—
Not much has changed...
Japanese are very xenophobic...
We still chanted racist epithets in training like bayonet drills all the way up to the war in Vietnam. Gulf War I was the first conflict in at least a hundred years in which the US militaries didn’t institutionalize racism from basic training on up. During WWII, it wasn’t just the military, in was endemic in the American culture, too.
That said, the Japanese raised it to a high art. But then that’s in their national character, isn’t it? Do everything to your utmost.