"Fists" (拳, Kobushi) is chapter 486 of the original Naruto manga.
Naruto and Sasuke are flung apart. Kakashi catches Naruto and Zetsu cushions Sasuke. Zetsu recalls Tobi, who advises Sasuke to retreat. Sasuke refuses until he can hear Naruto's answer about their fates. Naruto claims that they have reached a point where they are the only ones capable of fighting the other. If and when that happens, they will both die. Since they are friends, Naruto will bear Sasuke's hatred until then and eventually die for it. Sasuke accepts his conclusion, but promises that Naruto will be the only one to die when that day comes.