Tsunade was pressured into making Sai Sasuke's replacement in Team 7, but Naruto and Sakura were also met by a new group leader, Yamato. They set out to meet Sasori's spy and get information from him, possibly even capture him for further questioning. On their trip the group came to know each other better, but Naruto had already previously met Sai, who attacked him in Konoha. Although Sai exclaimed that he merely wanted to test his teammate a little bit. Sai had the habit of insulting others (unintentionally) and saying what's on his mind, not considering others' feelings... or rather, not understanding them, which caused alot of animosity between him and Naruto and Sakura. But Sakura was intrigued by Sai and sought to learn a little more about him; she found out that he's a painter and he told her that he was trained as a small child not to have any emotions and it's hard for him to understand emotions or even the bond that Sakura and Naruto have with Sasuke, admitting that he didn't even cry when his brother died. He also informed her that he has been trying to simulate emotions after learning what he reads in books, but nobody believes them. She came across a picture book that Sai was working on and asked if she could see it, but Sai told her that he didn't want anyone seeing it.

Back on their mission, the spy turned out to be Kabuto who was secretly a double agent, actually working for Orochimaru. He and Orochimaru planned on killing Sasori right then and there and that's when Team 7's plan fell apart, but Kabuto and Orochimaru too realized that they were tricked. The Kyuubi chakra began to flood out of Naruto as he sprouted four tails and attacked Orochimaru, scaring Sakura. Sakura and Yamato had a brief scuffle with Kabuto, but Sai was mysteriously absent in all of this. Kabuto informed Team 7 that he and Orochimaru don't want to fight them, saying that Akatsuki has been a thorn in their side and they're hoping that Team 7 can take out more of their members for them. With no mor ethreat, Yamato took the opportunity to suppress the Kyuubi's chakra within Naruto. While that took place, Sai confronted Orochimaru and offered an alliance, giving Orochimaru an envelope that he was ordered by Danzo to give to Orochimaru. The three took off, but Yamato's Wood Clone followed. Team 7 soon gave chase after Sakura found Sai's picture book laying on the ground. The team started to go through it, trying to figure out it's meaning and find out why he'd betray them. On their way, they came across Sai, having been hung by Orochimaru and Kabuto. This however was a trick meant to halt their pursuit, they followed still.

At Orochimaru's hidden base, it's revealed that the envelope contained detailed information on many powerful figures within Konoha and Danzo was hoping that they could help each other overthrow Tsunade since Danzo hates her and wants to be the Hokage. Orochimaru is intrigued and has Kabuto put Sai in a locked room. Team 7 are going through Sai's book and they notice that it stars two characters, both of their "stories" start on opposite sides of the book and seem to meet in the center, however the center pages are missing. They notice that one of the characters is Sai who is shown fighting different people on each page, and every next page shows him with something his previous opponent owned. This trend was the same with the other white-haired character, but they had no idea who it was. Team 7 would find Orochimaru's base and find Sai. There, they talked with him and he revealed what he told Orochimaru and what the true plan is... Orochimaru is a threat to Konoha and Sai was supposed to relate any new information about him back to Danzo so that Root can kill him. They talked a little more about Sai's book and he reveals that it's his brother in that book... or rather, they called each other "brother." Root is made up of orphans that Danzo trained to be perfect soldiers. Sakura asks if he's the one that killed his "brother," but Sai informs her that she's incorrect and that he died of illness. She tries to convince him that Sai did have a bond once and that he should understand what her and Naruto are going through. Sai feels like he may understand a little and agrees to help them find Sasuke, and they split up.

They open every door in Orochimaru's lair trying to find Sasuke, but Sai is the first to find him. Sasuke asks why Sai would disturb his sleep, and Sai informs Sasuke that he's supposed to kill him. Naruto and Sakura hear a large ruckus and go to see if Sai's ok. They find out that Sai wasn't only supposed to kill Orochimaru, he was supposed to kill Sasuke too... since he's a threat to Konoha aswell. Naruto attacks Sai, but Sai informs them that he was supposed to kill Sasuke, but he decided not to, wanting to learn more about "bonds." They find Sasuke watching them from up high and after a brief talk, Sasuke attacks Naruto but Sai stops him from killing Naruto. After a brief scuffle, Kabuto and Orochimaru appear and stop Sasuke, telling him that they have a temporary truce with Team 7 and leave.

Team 7 later return to Konoha where Sai meets Chouji and Ino. Sai thinks to himself that a book said that a good way to make friends was to give people nicknames, so he was about to call Chouji a fatass... but Naruto stopped him. Seeing Chouji get defensive and realizing what Sakura did earlier when he called her "butt ugly," he realized that people don't like to hear the truth, so he calls Ino "beautiful," which makes her blush... but angers Sakura.

Powers/Techniques

So far Sai has displayed a Jutsu to make his art three-dimensional. The full extent of these abilities are unknown, but like "Clone" techniques, they will disperse after taking damage.