I'm not KISHI........so,I maybe wrong......
To aweken a MS the user need to killed a dear one of his or her......
so,why KAKASHI HAVE MS........How he gain that ?????
RIN WAS ON OF KAKASHIS DEAREST FRIEND........
KAKASHI KILLED RIN FOR SOME REASON[I DON'T KNOW]......
SO,thats how KAKASHI GAIN...