Yes, that is exactly what we're doing. I couldn't find the article I read about Japan specifically a few years ago. Japan wanted the US to remove our base on Okinawa (IIRC) after so many sexual assaults on Japanese women by US soldiers. The US refused. That is, by definition, occupation.

I don't think there have been any referendums in Germany on the subject, and I'll bet there won't be any soon, because for sure a majority under 50 would want the US gone. After Trump tried to extort Germany into buying natural gas from the US rather than Russia, maybe even the over 50s would vote US (pun intended) out. And 100% the US would refuse there too.

Wikileaks revealed Hillary Clinton (as US Sec. of State) writing about how the US doesn't want Korea to reunite, because divided they are less of an economic threat to the US, and we work to keep it that way.

So "Yes" the US is occupying Japan, Germany and South Korea.