Origin = Japanese Girls/Anime Shows
Then taken on by American curry smelling immigrants/queers.
Uh, no hip hop has been doing this from back in the day. Since Japan is obsessed with american culture they started doing it, but the Japanese girls do it in a cutesy way.
And cam'ron is a American rapper. Jadakiss used No Homo to death a few yrs ago, it is still used occasionally by some urban New yorkers, if they say something that might miscontrued as gay, ex: "those pants are a little to tight on you, no homo", one doesn't want to give impression you were looking at another guys ass.