A Plea from a Friend

is episode 133 of the original Naruto anime.

Synopsis
Sasuke is dumbstruck by Naruto's display of power and asks Naruto what he is. In tears, Naruto says that he is Sasuke's friend and will not let him defect to Orochimaru even if it means breaking every bone in Sasuke's body. The boys fight, and Sasuke struggles to counter Naruto's increased speed and strength, not using clones and even deflecting Sasuke's Great Fireball Technique with a mere scream. After giving a severe beating, Naruto pins Sasuke against the rock wall and asks him if he has come to senses yet. A quiet Sasuke burst out in rage and tells Naruto that he could not possibly understand what it feels like to lose his whole family, because Naruto was alone from the start. He tackles him and they both fall to the water.

Naruto admits that whereas he knows nothing about parents or siblings, he thinks of his time with Iruka to be like having a father, and states that when with Sasuke, he thinks he knows what having a brother feels like. Naruto states that to protect this bond, he will stop Sasuke no matter what. Sasuke resists Naruto's appeals and and says that it is too late for him to go back. He puts on his forehead protector and calls for Naruto to come, that he will break the bonds of their friendship, also saying there would be no more talk. A third tomoe appears in Sasuke's Sharingan signifying that it is now fully mature. Naruto asks Sasuke why he's bothering with the headband if he seeks to break his bond with Naruto and the rest of Konohagakure. Sasuke explains that he is recognizing Naruto as an equal, though he once again taunts that Naruto won't even be able to scratch his forehead. Elsewhere, Kakashi catches up to Pakkun and the two hurry to stop Sasuke and Naruto.

Naruto and Sasuke resume their battle, but this time Sasuke has the upper hand, harnessing the full power of the Sharingan. Naruto's taijutsu is no match for Sasuke's power to read his movements, equalling it out with new hand-to-hand combat that beats Naruto ruthlessly. Sasuke easily thrashes his clones, until Naruto uses a chain of shadow clones to throw Sasuke into the cliff wall, but Sasuke counters with Fire Release: Dragon Fire Technique, scorching every single shadow clone. A half-conscious Naruto again implores Sasuke to stop, but Sasuke declares it too late and as a finishing move, he mercilessly throws him into the air pile drives an upside down Naruto into the ground below which was made by the impact made an opening in the water, a move that should have broken his neck or killed him. Sasuke leaves and coughs tired. Inside Naruto's subconscious, the Nine-Tailed Fox says that Naruto is too weak and that the boy should be thankful to him and The Fourth Hokage. Seemingly defeated, the fox's red chakra begins pouring out of Naruto, who slowly gets up and punches the shocked Sasuke several yards back into the water. Naruto grows a chakra tail, moves like a fox, and attacks Sasuke once more. Sasuke struggles against Naruto's onslaught and notices that the red chakra seems to have a mind of its own.

Sasuke tries using his cursed seal, but even that is ineffective against Naruto's attacks. He then uses one arm to pull him back and land an earth-shaking punch on him. Sasuke laughs and says that Naruto has given him no choice but to use the second level of his cursed seal. As the seal transforms his body, Sasuke's hair grows longer, his nails extend, and his skin turns purple. He acknowledges that Naruto possesses a special power, but says that he is more special.