On a tour of the south Pacific, Eleanor Roosevelt bragged about the Marines killing so many Japs. She didn’t say Japanese, she said Japs.
Micronesia is a boneyard of ships and planes
When I make a comment about WWII I always use “Jap”, Modern-day discussions I use Japanese. I think that my old man used the same convention. Although I do know he’d be real disappointed in me owning some Japanese built cars!