I think there were some threads about this, so this is what I think, kakashi got his sharingan from Obito Uchiha in the third great ninja war, obito wanted do give him his sharingan when he was crashed by a big rock. The two of them wanted to save there companion (Rin). she's a medical ninja from their team leaded by Minato Namikaze. Rin put obitos eye in kakashis eye (than was hurt, he even now has a mark from it) . Cuz it's kind of Kakashi's fult ( I don't really think that) Obito diead ( his best friend) and itachi said to awake your Mangekyo u need to kill your closest friend, that's why Kakashi has mangekyo. But he needed power to awake it so he did it when Naruto was with Jiraya. He probubly trained. :kakashi: That's all !