Tales of a Gutsy Ninja ~Jiraiya Ninja Scroll~ Part 1

is episode 127 of the Naruto: Shippūden anime.

Synopsis
Back in the times of the Second Hokage, the young Jiraiya, Orochimaru, and Tsunade are assigned to Hiruzen Sarutobi's platoon. He had the three of them try to take the two bells he kept on his person, in which Jiraiya fell for a trap and thus became the one tied to a log. Hiruzen Sarutobi scolds Jiraiya, and proceeds to summon Monkey King Enma, thus giving Jiraiya a motive as to train harder. Being fascinated by Sarutobi's Summoning Technique, Jiraiya one day attempts it himself, only to teleport himself to Mount Myōboku. There, Jiraiya trains under Fukasaku and meets the Great Toad Sage who has a vision of his future. During the next few years, Jiraiya proceeds to train under Fukusaku as well as complete missions with his team in the meantime. When his training with Fukusaku had been completed, Jiraiya goes on a journey with the goal to fulfil his destiny. Before returning to Konoha, Jiraiya is shown at various locations, in which he sees unknown ninja whom were later used as the Six Paths of Pain. Jiraiya then proceeds to fight with an unknown ninja, and manages to leave a scar on his forehead before the end of their battle.

Trivia

 * This episode as well as the subsequent Part II is a collection of a series of events that occur throughout the manga in the form of flashbacks.
 * It aired at the same time as episode 128.