Naruto Shippūden - Season 2 - Eps 48: Bonds
Yamato and the team enter Sai's room and confront him while Kabuto makes his way there as well. Sai tells Team Kakashi that not only was he to help with Konoha's destruction but also act as a spy against Orochimaru. Yamato reveals the secret of "Root"- its members were trained like Kirigakure's students in that they had to kill their friends so as to eliminate their emotions. Sakura returns Sai's book to him, remarking that he still has emotions because he treasures it. Sai then tells the group about his bond with his brother. Finally the team decides what to do about Sai's betrayal outside the lair. In doing so, Naruto tells the group about his own bonds and about how far he's willing to go to bring Sasuke back.
About Naruto Shippūden

Title: Naruto Shippūden
First Air Date: 2007-02-15
Last Air Date: 2017-03-23
Status: Ended
Rating: 8.538/10 (from 8290 votes)
Language: JA
Seasons: 21
Total Episodes: 500
Network: TV Tokyo
Genres: Animation, Action & Adventure, Sci-Fi & Fantasy
Production Companies: TV Tokyo, Pierrot, Sound Box, Rakuonsha, Aniplex
Synopsis
After 2 and a half years Naruto finally returns to his village of Konoha, and sets about putting his ambitions to work. It will not be easy though as he has amassed a few more dangerous enemies, in the likes of the shinobi organization; Akatsuki.
Cast

Junko Takeuchi
Naruto Uzumaki (voice)

Noriaki Sugiyama
Sasuke Uchiha (voice)

Chie Nakamura
Sakura Haruno (voice)

Kazuhiko Inoue
Kakashi Hatake (voice)

Showtaro Morikubo
Shikamaru Nara (voice)

Satoshi Hino
Sai (voice)

Akira Ishida
Gaara (voice)

Hideo Ishikawa
Itachi Uchiha (voice)

Koichi Tochika
Neji Hyuga (voice)

Keiko Nemoto
Shizune (voice)