Sasuke is a member of the Uchiha clan, a highly skilled clan of ninjas allied to the village of Konohagakure. His primary motivation throughout the series is to avenge the destruction of his entire clan by killing his brother, Itachi Uchiha, a task he pursues at all costs. While he was initially cold and singularly driven by his revenge, he becomes more empathetic through his relationships with other characters, notably Naruto Uzumaki, whom he comes to consider as a rival.

Sasuke's childhood, as told over the course of Naruto manga volume twenty-five, was spent living in the shadow of his older brother, Itachi Uchiha, whose natural abilities had made him the pride of the Uchiha clan. As a result, Sasuke's family largely ignored him, forcing Sasuke to constantly try to win their recognition. Sasuke, however, was never able to surpass the milestones set in place by his brother, leaving Itachi to be the only one to appreciate Sasuke's efforts.t was not until Itachi had a falling out with his family that Sasuke began to receive his family's attention, his father in particular taking a keen interest in Sasuke's training. In tandem with finally being able to enjoy his family's company, Sasuke was encouraged to not follow in Itachi's footsteps.Upon returning home from ninja school one day, Sasuke found the street littered with the corpses of the Uchiha clan. After running home to alert his family to the tragedy, Sasuke found Itachi standing over their parents' bodies. Realizing Itachi was responsible for the murders, Sasuke ran for safety, only to be stopped by Itachi's proclamation that he would be spared. Sasuke, having always been trying to surpass Itachi, was as a result the only person who could someday prove a match for him.Wanting to eventually test his abilities with Sasuke's own, Itachi encouraged Sasuke to get stronger by living a life of hate and anger towards him, with the sole purpose in life being to avenge the clan. Itachi left, and Sasuke was left to consider his words in the absence of family. Longing for the love of his parents that he was now denied, Sasuke agreed to live his life as Itachi had instructed, wanting to kill his brother at all costs.After his assignment to Team 7 at the start of the series, Sasuke displays an immediate confidence in his abilities. He is as such unwilling to work with his teammates, Naruto Uzumaki or Sakura Haruno, believing their skills to pale in comparison to his own and therefore making them useless if he is to ever kill Itachi.These perceptions are quickly proven wrong, for despite their failings, Sakura is an excellent source of information and competition with Naruto acts as an effective way to get stronger.While his confidence in himself is ever-present throughout the series, Sasuke slowly begins to rely on those close to him over the course of Part I. This begins to result in his risking his own life to save those of his friends, even though his death would leave him unable to gain vengeance on Itachi.He becomes complacent with his life in Konohagakure, satisfied with the speed of his growth as a ninja. Similar to how Itachi used the slaughter of the Uchiha clan to measure his ability, Sasuke uses his battles with the various characters he meets in Part I to gauge his increase in strength. Through his battles with Haku, Rock Lee, and Gaara, Sasuke is able to test his abilities against those of progressively stronger ninja, discover his weakpoints, and carry away something new from the battle. Once Naruto begins to prove his worth, Sasuke starts to yearn for a battle with him as well.Naruto, however, gains strength at a much more rapid rate than Sasuke, even learning the Rasengan, an attack stronger than Sasuke's Chidori. This, coupled with Sasuke's quick defeat by Itachi during his short return to Konohagakure, leads Sasuke to believe his growth is slowing. In an attempt to reassess his strength, he begins to treat his friends as opponents so as to test his abilities against their own.