Big Adventure! The Quest for the Fourth Hokage's Legacy Part 1

is episode 170 of the Naruto: Shippūden anime.

Synopsis
The story goes back to right before the start of the final rounds of the Chūnin Exam. As Naruto trains in preparation for his upcoming match, he hears Jiraiya speak of “the Fourth Hokage’s legacy”.

Trivia

 * In this episode you can spot the poster, for Naruto Shippūden 4: The Lost Tower movie.