legit question. it's the same sound my Korean friends make when they laugh so I assumed it was just an imitation of that, but I can tell from how people reacted to Mishima's use there's somethin bad about it?
There's a bit of a stigma to using it, if that makes sense. I notice a lot of, forgive my french; "newfags" tend to use kek. Most people say it ironically now, but it still has the same connotation as lol or lmao.