@Thejobbernowl it's not just Japan, Kpop fans in Korea are extreme... they sometimes (physically) fight each other over which guy in the group is better...
And at one point I knew a Korean guy living in Germany through a game, he was quite a looker, but he only dared to show his pictures on discord to at first just me and later on to a few of the other players, because he was stalked on the internet... he deleted his facebook because random girls would start talking to him just because he's (a handsome) Korean...
And among visual kei fans, there's this story of a German girl that went to Japan to meet the vocalist of a band, she had completely taken her dellusions for reality, saying she was 100% sure she was going to marry the guy... of course the guy didn't even know her and wanted nothing to do with her.
But pretty sure stuff like this happens to western boybands too, fangirls can be super scary, lol.