Kakashi is actually Naruto, from the future. He is actually here to protect himself so that he doesn't get the scar he has on his eye. He is also protecting Naruto (himself) from Sasuke who is actually Naruto's twin. But they don't look alike because Kakashi used a Henge Jutsu on Naruto to protect himelf. Kakashi is actually what Naruto should look like. Then Orochimaru tells Sasuke and he gets really mad and leaves. Itachi is actually Sasuke's father, that's why he doesn't kill him, and Kakashi is trying to train Naruto so that HE can be the one that kills Itachi, because he knows that Sasuke is also going to go crazy and kill everyone in the school unless Itachi dies first.