Time heals all wounds. Though both Naruto and Kurama started as nothing more than enemies, with Kurama always trying to take over Naruto's body, as time passed, Kurama took a liking to his character. Naruto's constant kindness to humans and the other Tailed-Beasts managed to change his perspective on all humans, and for the first time in his life, he put his faith in a human (Naruto).