Obito grew up not knowing who his parents were; in the anime, he was left in the care of hisgrandmother. Feeling alone in the world, Obito dreamed of becoming Hokage so that the people of the village would acknowledge his existence. He enrolled in the Academy to help him achieve that goal, where he developed a one-sided rivalry with Kakashi Hatake, whose natural talent and popularity he was jealous of. He also became a close friend of Rin Nohara, whom he eventually fell in love with. After finally graduating some years later, Obito, Rin, and Kakashi were placed on ateam under the leadership of Minato Namikaze.
In the anime, as a final qualifying test, Minato gave the team a bell test to test their cooperation skills. Obito could not accomplish this on his own but, by joining forces with Rin and Kakashi, they succeeded in taking the bells, teaching Obito the value of teamwork. The team later participated in the Chūnin Exams, where Obito was defeated in the third round in a one-on-one match with Might Guy. Kakashi would go on to defeat Guy in a subsequent match, promoting him to chūninand impressing Rin. Eager for Rin's attention, Obito trained relentlessly, eventually rising to the rank of chūnin himself. His excitement was short-lived as Kakashi soon afterwards became a jōnin, once again earning Rin's praise and Obito's resentment.
During the Third Shinobi World War, Kakashi was placed in charge of the team for a mission to destroy the Kannabi Bridge, which would hinder Iwagakure from using Kusagakure as a relief point. Before beginning the mission, Minato and Rin gave gifts to Kakashi to celebrate his promotion to jōnin, though Obito had "forgotten", straining their already poor relationship. Minato was soon called to the front lines, leaving the team to complete the mission alone under Kakashi's command. The three were discovered by Iwa-nin along the way and Rin was captured. Kakashi elected to abandon Rin, believing it was more important to finish the mission before concerning themselves with her safety. Obito became enraged at the idea and insisted that they focus on her rescue. When Kakashi refused, Obito left on his own, remarking that Kakashi was worse than trash for abandoning his friends.
Obito located the cave the Iwa-nin were using as a hideout, but was found by a camouflaged Taisekibefore he could launch a rescue. Kakashi, moved by Obito's earlier words, arrived in time to save him from Taiseki's attack, but lost his left eye in the process. From his desire to help Kakashi, Obito awakened his Sharingan, allowing him to see through Taiseki's camouflage and kill him. Obito and Kakashi infiltrated the cave and released Rin from her restraints. Her captor, Kakkō, caused the cave to collapse around them. As the team ran for the exit, Kakashi was struck in his blind spot and fell. When Obito noticed that Kakashi was about to be hit by a falling boulder, Obito pushed him out of the way and became trapped in his place.