In the Fourth Great Ninja War, the village's knuckleheaded ninja, Naruto Uzumaki, formed ties with Kurama. In 'Naruto: Shippuden' episode 329 titled 'Two-Man Team,' he turns on his first and greatest Fox, aka The Nine-Tails, to become an ally and friend.
After having a deep talk with his father Minato, Naruto decides that he should at least show some appreciation for the power Kurama gave him. There is change of heart towards both Ninetailed Foxes after all: those two are indeed close friends now!