Does it make sense to use 上京 in a fantasy setting where the geography is totally different from our world? In my mind this word is very strongly associated with Tokyo. I know that according to some dictionaries it can technically refer to moving to any capital city, but still I can't help but feel that it sounds slightly odd in other contexts. Did I get the wrong impression?
Here is a scene from ハクメイとミコチ that inspired this question.