For a Friend…

is episode 132 of the original Naruto anime.

Synopsis
Kakashi learns of Sasuke's defection and immediately goes after him. Meanwhile, believing Naruto to be his closest friend, Sasuke prepares to kill him, finding the loss of Naruto to be an acceptable price for the Mangekyō Sharingan. Naruto's Rasengan and Sasuke's Chidori clash, though neither is capable of overpowering the other. Activating his cursed seal in order to gain the upperhand, Sasuke uses his Chidori to pierce through Naruto, just missing his heart. While Sasuke thinks the battle to be won, the demon fox's chakra begins to envelop Naruto and the wound Sasuke inflicted starts to heal. Infused with the demon fox's strength and now willing to break Sasuke's body in order to bring him home, Naruto attacks.