I have to disagree. I have friends that know me very well but that doesn't stop them from being KY. KY isn't not knowing your friends, it's not being able to read the atmosphere. When I first moved to Japan, I was very KY, but I still knew my friends well.

Have you seen the anime Kimi Ni Todoke? Or the drama? Sadako was very KY at the beginning, but outgrew it as time went by.