@T.E.D. Will it be on-topic If I ask a question that if American drafted constitution of Post-WW2 Japan officially dissolved the Empire, why does Japan have an emperor today?

Or will it be better served on politics SE?

In theory that's on-topic. However, we are a very tough stack to ask a question on and keep it open. Our users currently are really big on questions showing some kind of "preliminary research" So I'd highly advise throwing in a link or two to things you read that make you wonder about this question.

I don't hang out enough on Politics to know how it would be received there.

@T.E.D. Thanks. I have done some research but of course I need help of someone who understands the Japanese constitution better than I do based on my brief skimming

Yeah, if you can demonstrate that, you should be OK. Although I will warn you, if you want to know if technically he should still be considered an Emperor, that probably is more of a politics question. But if you want to know why the US let him keep his position and titles at the end of WWII, that's more our baliwyck