Firstly the "American uniform" is from a film. And the film is British, so what a fail of an argument, especially seeing as it's set in a catholic school in the uk. The film is called St Trinians just in case you were wondering. So just for that reason I'm picking the Japanese side :P if you wanted to, you could EASILY get slutty sailor uniforms.

OP is biased, you get slutty uniforms everywhere.