Naruto is assigned alongside Sasuke Uchiha, whom he often competes against, and Sakura Haruno, whom he has a crush on, to form a three-person team named Team 7 under an experienced and severe sensei, the elite ninja Kakashi Hatake. Like all the ninja teams from every village, Team 7 is charged with completing missions requested by villagers, such as doing chores or being bodyguards. After several missions, most notably their mission to Wave Country as Tazuna the bridge builder's guards, Kakashi allows Team 7 to participate in a ninja exam in which they can advance to a higher rank, and thus, take part in more difficult missions. During the exams, Orochimaru, a criminal at the top of Konoha's most wanted list, attacks Konoha and kills the Third Hokage in an act of revenge. This forces one of the three legendary ninja, Jiraiya, to search for his former teammate Tsunade, who has been nominated to become the Fifth Hokage. During the search, it is revealed that Orochimaru desires to acquire Sasuke due to his powerful genetic heritage, the Sharingan. Believing Orochimaru will be able to give him the strength needed to kill his brother Itachi, who destroyed his clan, Sasuke eventually joins him after a humiliating defeat at his brother's hands. Tsunade sends a group of ninja including Naruto to make Sasuke return to Konoha, but Naruto is unable to defeat him and bring him back to the village. Naruto does not give up on Sasuke, however, and he leaves Konoha to train for two and a half years under Jiraiya's tutelage in order to prepare himself for the next time he encounters Sasuke.