"Keep on Training: Pop Goes the Water Balloon!" (根性!!!割れろ水風船, Konjō!!! Warero Mizufūsen) is episode 87 of the original Naruto anime.
Soon after his training begins, Naruto finds himself unable to make any progress. After asking Jiraiya for tips, Naruto decides he'll master the jutsu in three days. Jiraiya doubts the likelihood that Naruto will live up to this promise, explaining that the technique's creator, the Fourth Hokage, took three years to develop the Rasengan in its current form. He then goes on to explain that popping the water balloon is only one of three steps to mastering the technique, and leaves Naruto to resume his training. Over the next three days, Naruto practises by himself in the woods as Jiraiya mingles with the women on the town. He is unable to find success, until he spots the hotel's cat spinning and bursting his water balloon. Seeing this, Naruto comes up with an idea to burst the water balloon - by keeping it steady in his left hand, he uses his right hand to create chakra and rotate the water inside the balloon in different directions until it pops. Although unorthodox, as it requires two hands instead of one, Jiraiya states that he has passed the first stage and that they are moving on to stage two.
The second stage involve bursting the balloon again; however, unlike the first, the second stage involves a regular balloon instead of a water balloon, making it harder to pop. Naruto demands help, but Jiraiya states that Naruto isn't a child anymore and that he must figure things out. As Naruto continues to train over the next several days, Jiraiya tells Naruto to go to town and fetch food for the two of them. While in town, Naruto witnesses a father and a son sharing a popsicle. Naruto asks Jiraiya if he'd be willing to stay and spend the day and help him, but Jiraiya repeats his earlier words and tells Naruto to do things himself. Over the next three weeks, Jiraiya leaves Naruto to his own devices and continues to mingle with the women in town. Feeling immense pain his arms and still unable to burst the balloon, Naruto decides to hold the balloon in both hands and force chakra into the balloon until it bursts, despite the pain he feels in both hands. Pushing himself to his limit, Naruto manages to cause a hole in the balloon. Although disappointed that he wasn't able to burst it, Naruto is congratulated by Jiraiya. Jiraiya offers a popsicle to Naruto, who accepts it happily.