I dunno why everyone gangs on Kakashi. Let me explain.
The guy is one of the best characters Kishimoto created. He was neglected for a long time in Part II, true, but still. See it in this light : he actually has a good story. He has something that he regrets. He has deaths of both his best friends basically on his hands, and he lived to see his sensei die. The guy doesn't have much in his life and, in loving memory of his best friend Obito, he teaches kids his philosophy.
Then, he finds out this guy is alive and is trying to kill him for real. His guilt and his confusion play a huge roll in this fight, and Naruto's speech about protecting friends, which are Obito's own words, made him stand up and fight in the very end of the chapter.
The reason that he actually didn't go : fuck you Obito, imma gonna fuck you up! is what actually makes him a great character. Without it, we would only have the little Uzumaki moron shouting shit which make me puke my fucking guts out.