Small question: What does "KC" actually stand for? It means "headbow" but I'm still at a loss.

I'm just curious because I see a lot of sets that list "skirt/jsk/op + kc set!" and I have no idea what KC even stands for.

on Japanese sites, "katyusha" means headbow as well, but is that what became "KC?"

If anyone could answer this small silly question I'd be grateful. Thanks!