The Truth Is....
cosplay started in the US! I'm proud to admit to being one of the first copy-cat dressers here in the state of Maine in 1955. I dyed my long underwear blue and painted a big "S" on my chest; put a big red towel around my neck.
I flew off porches and leaped from trees & phone booths as my hero SUPERMAN did. I also wore a white hat & black mask with my trusty six guns and next door neighbor as Tonto! The neighbors big Great Dane was my faithful horse Silver. Later it was buckskins, coon skin hat, and trusty flintlock, Betsy, as I explored the deep forest. I guess we didn't call it "cosplay" back then, but it was the same I think.
Frank