"Iruka's Ordeal" (イルカの試練, Iruka no Shiren) is episode 177 of the Naruto: Shippūden anime.
After being denied a chance to join his classmates on a "Test of Courage", Naruto decides to pull a prank on them. Since Iruka reprimanded him, Naruto declares that he wouldn't return to the Academy because he realised that Iruka is looking at him in the same manner that the other villagers did. While Naruto is walking around the village, he runs into the same group of boys he pranked in the cemetery. Their leader, Hibachi, tricks Naruto by offering him a chance to join their group, telling him that a patrol unit had fought some enemy ninja in the back hills the day before, if he could bring back something from the battle site. Later in class, Shikamaru exposes the trick that the boys played on Naruto. While Naruto is running through the forest, excited at the prospect of having friends, he is followed by unseen ninja.