The Promise That Could Not Be Kept

is episode 135 of the original Naruto anime.

Synopsis
The retrieval team is brought back to Konoha where, despite the severity of their injuries, all fully recover. When Naruto comes to, he apologizes to [Sakura] for not living up to his promise and bringing Sasuke back. However, she says that he'll do it someday, going on to say that when that day comes, they'll do it together. Jiraiya offers Naruto a chance to leave with him for three years to train. Naruto accepts, and Jiraiya tells him they'll leave whenever he's ready. Elsewhere, Sasuke arrives at Orochimaru's lair where he soon proves himself worthy of Orochimaru's guidance. Meanwhile, Akatsuki assembles, ready to start their mission three years from now.