I realize when I play any characters other then ayane, ein and hayabusa in story mode, I occasionaly fight against kasumi clone in other stage than the clone lab. The first time I realize it it when I was playing as tina in story mode and when I reach the fifth stage(I think) I was fighting againgt kasumi in the firework area, in the begining of the match when characters are saying they quote, kasumi didn't not talk, I first thought it was a occasionly bug, but when I lose(which make kasumi the winner), kasumi say the same quote as her clone: "this is a mistake". and the second time is when I was playing as bass in story mode and the same thing happen but only this time she was in the arial garden..and what convince me more is that she is wearing the pink or black ninja costume.
here the clue in case u want to try, I think it work with any characters in story mode if she or he don't have a cutscene with kasumi,the only think u need it luck to bump on her when u fighting from stage to stage cuz she only occasionaly appear(sometime is the real kasumi u fighting against with so dont confuse with her) but here the clue to know it the clone and not kasumi herserlf:
- she didnt not say anything it the beginning of the match, she just get in position
- she will only wear her pink or black ninja costume
- no matter how many time she win, she will say the same quote: "this is a mistake"

I don't no maybe im wrong..
anyway thanx for reading it
and sorry for my bad english