Shortly after Naruto was born, his father, the Fourth Hokage, sealed the dangerous Nine-Tailed Demon Fox within Naruto's body at the cost of his own life, leaving Naruto without a family. As a result of him being the demon fox's host, the villagers of Konoha hold a strong animosity for Naruto. Thus, he never has a source of love or attention during his early childhood. Desiring what he lacks in his early life, Naruto dreams of becoming Hokage, the village's leader, hoping that it will bring him the villagers' recognition and respect. To assist him in gaining this title, Naruto possesses a fierce determination, always confident he can complete a given task with relative ease. Although he does not always complete his tasks, Naruto's efforts prove successful as the series progresses; many characters reach the conclusion that Naruto will someday be an excellent Hokage. Since his childhood, Naruto has commonly made jokes to attract attention. He sometimes goes to the point of transforming into a naked woman to ridicule whoever may be bothering him. This even causes his pupil, Konohamaru Sarutobi, to emulate his techniques and jokes.
Occasionally, Naruto's determination results in those around him adopting some of his traits, such that in Part II his teacher, Kakashi Hatake, notes this to be Naruto's unique power. In the aftermath of fighting Naruto, Gaara discovers that true strength is found in fighting for one's friends, not for oneself. These character metamorphoses serve as the moral for the arcs they take place in, and subsequently become the creed for the particular character's life. After Jiraiya's death, Naruto becomes determinated to kill Pain, Jiraiya's murderer. However, he later decides not to kill Pain and that he will break the hatred's cycle as Jiraiya wanted.
Through his ability to change others, Naruto gains the friends he lacks during his childhood. Among the many friendships he forms, none are more prominent in the series than those he has with his two teammates: Sasuke Uchiha and Sakura Haruno. With Sasuke, Naruto shares a highly competitive relationship which he likens to brotherhood. Though Sasuke betrays Naruto and the rest of Konoha at the end of Part I, Naruto maintains his attachment to Sasuke, readily lashing out at anyone who speaks poorly of him. Naruto possesses a deep dedication to Sakura, rooted in the crush he has had on her for years. Naruto's commitment to Sakura is so strong that he will do anything to make her happy, vowing to someday return Sasuke to Konoha for her sake.
source : wikipedia.org