This is a pivotal lore episode where explains his tragic past to Naruto, revealing the birth of his ideology and the Akatsuki.
There are two episodes titled within the Naruto franchise, belonging to the original series and the Shippuden sequel. Naruto Shippuden Episode 173: "Origin of Pain" Naruto Episode 173
In the Boruto sequel series, this episode occurs during the "Kara Actuation" arc. This is a pivotal lore episode where explains
Naruto, with the help of the Nine-Tails' chakra, defeats the scientist Amachi . He then summons Gamabunta to evaporate the massive sea monster, Umibōzu, which is threatening the group. Naruto, with the help of the Nine-Tails' chakra,
The story follows Nagato, Yahiko, and Konan as they survive the war-torn Amegakure and eventually meet Jiraiya , who agrees to train them.
The episode details the betrayal by Hanzo of the Salamander and Danzo Shimura , which led to Yahiko's self-sacrifice. This "second great pain" transformed Nagato into Pain, leading him to believe true peace can only be achieved through shared suffering.
They discover a God Tree sapling being grown illegally, which Victor plans to use as a source of power by feeding it humans.