A Town of Outlaws, The Shadow of the Fūma Clan

is episode 137 of the original Naruto anime.

Synopsis
Naruto, Sakura, and Jiraiya end up in a town that is worse than the one out of which they were chased. Jiraiya heads off and leaves Naruto and Sakura to get food. Along the way, they find the female ninja that attacked them before. Because the ninja is injured, Naruto and Sakura fight some Sound ninja to save her. They then learn that her name is Sasame, and that she is looking for her cousin Arashi, who went with several members of their clan to join Orochimaru to revive the clan.