What I mean is, US dropped two bombs on Japan killing thousands and then was involved in the Korean War (which I don’t know much about).
Yet Japan didn’t seem to have the hatred for Americans as the North Koreans do, it never became part of their propaganda (or did it?). What happened in these countries to manifest different views on Americans?
(What I’m trying to hint here as well is that what the US did to Japan is probably worse than what they did to NK on a macro scale?)
I think you're underestimating the amount of death and destruction from American bombing in both Japan and Korea. While you're waiting for further answers about their post-war trajectories, you should check out this precise answer about the fire-bombing of Tokyo in WWII from /u/DBHT14 and a link to furher information about bombing of Japanese cities from /u/restricteddata . The firebombing killed many more people than the atomic bombs and leveled many Japanese cities.
The U.S. didn't drop atomic bombs in Korea, true, but they carried out an absolutely stunning carpet bombing of North Korea. See this thread with answers by /u/belisaurius , /u/iveymikey, and /u/dsk_oz .
(What I’m trying to hint here as well is that what the US did to Japan is probably worse than what they did to NK on a macro scale?)
It's difficult to calculate numbers in Korea, and both bombing campaigns caused lots of death and suffering, but no, North Korea definitely fared worse on the macro scale.