"Cross-Examination" (詰問, Kitsumon) is chapter 538 of the original Naruto manga.
As Naruto (in Nine-Tails Chakra Mode) and Killer B head towards the battle field, the Nine-Tails pulls Naruto into his subconscious and berates him for squandering its chakra like that. Naruto and the fox have a conversation and the fox tells him to stop being naive as there was no way he could shoulder the hatred of an entire war and Sasuke. After a flashback of Naruto and Sasuke while in the Academy, Naruto walks into the Nine-Tails' cage and brings down the torii to pin the fox down. Naruto then stares dead into the Nine-Tails' eye and brimming with confidence tells him that he will do something about the war and Sasuke.