If we are being honest Japan's population was pretty well whipped into anti American fury even without the camps.

The Pacific War was in as many instances the culmination of 60 years of racial tension as competing geopolitical interests. Japan's press was squarely under the thumb of the military, to the extent that by the 30's PR officers would review and could ruin or close a publication just by word of mouth.

During the war we are told how each week the Editors of Tokyo's remaining papers would gather for essentially a business lunch with several Staff officers. There they would be given reports to turn into stories, or have their approved stories read aloud for support or ones found that were not in favor publicly shamed. While at times they would then name individual reporters to remove from certain beats, or to fire so they could be drafted.

All that is to say is that long before internment the mass narrative of the Japanese population was already one drawn along bloodlines. Of the pure Yamato race pushing back against the mongrel imperialists. Met of course by the Western narrative of the Yellow Peril. Hence you have scenes of spontaneous celebrations in much of Japan at the news of Pearl harbor. When you reach that point you sort of can't get any more radicalized as an entire country.

From there though it does become very difficult to tease out the competing trends of existing racism. real news, propaganda inflation, and outright fabrication. Stories about Jimmy Doolittle's Child Killing Raiders bombing schools are as good as the evil Americans locking up your neighbors cousins.

Ian W. Toll's new Pacific trilogy is a great place to look, really in the end going to be one of the best treatments of the Pacific War in decades.