Kakashi Hatake (はたけカカシ) is a jōnin-level shinobi from Konohagakure and the leader of Team 7. He is known worldwide for his use of the Sharingan, earning him the moniker Copy Ninja Kakashi (コピー忍者のカカシ, Kopī Ninja no Kakashi) and Kakashi of the Sharingan.
Kakashi is the son of Sakumo Hatake, also known as the "Konoha's White Fang". His mother apparently died when he was young. Kakashi has been known since a young age as an extremely gifted prodigy, regarded by many as the best of his generation. He had received top marks and had shown an innate aptitude for the ninja arts while in the academy. This permitted him to graduate from it in a single year at the top of his class at the age of 5, and then becoming a chūnin a year later.
Kakashi was teamed with Obito Uchiha and Rin under the leadership of Minato Namikaze. At the age of 13, soon after becoming a jōnin, Kakashi was assigned to lead Obito and Rin on a mission that would benefit Konoha in the ongoing Third Shinobi World War. Knowing his life was at an end, Obito instructed Rin to implant his left Sharingan into Kakashi's damaged eye. Rin complied, and as soon as the surgery was completed Kakashi used the Sharingan and his Chidori to kill Kakkō. He then returned to Obito to see if there was anything he could do for him, but the place was turning into shambles, forcing Kakashi and Rin to leave him behind.
Personality
Kakashi became more stern and serious following his father's death, following all the rules and scorning any who disobeyed them, like his team-mate Obito Uchiha. This caused Obito to resent Kakashi, as Kakashi showed little kindness to his team-mate. This changed when Obito was mortally wounded in a mission, and Kakashi and Obito became friends in the latter's final moments.
Obito's death had a huge impact on Kakashi's personality. He is now more cheerful and shows greater concern for his team-mates and students, placing their safety over the successful completion of a mission, as well as believing that teamwork is essential to overall success as a team.
Kakashi has a rather solitary and matter-of-fact attitude. His calm and detached demeanour has been called "cool, hip, and trendy" many times by Might Guy. Despite his increasingly growing reputation and prowess as a ninja, Kakashi has shown no signs of arrogance, and is rather modest about his abilities, as shown when he readily praises others for leaps in their combat abilities and stating on more than one occasion that Naruto has surpassed him in power.
Abilities
Kakashi is a natural genius, evidenced by the speed he rose through the ninja ranks; he graduated from the Academy at age 5, becoming a chūnin at age 6, a jōnin at 13, and had a long tenure as an ANBU. During his career he has amassed a technique arsenal of over a thousand different techniques, making him Konoha's expert in the field. His various accomplishments have earned him much praise by his fellow Konoha ninja and he holds a position of great influence. Pain was so concerned by Kakashi's abilities that he tried to kill him for fear that he would someday interfere with Akatsuki's plans. This concern was later validated in the Fourth Shinobi World War when Kakashi and Guy together managed to hold off several "Version 2" state jinchūriki by themselves.
In Part II, Naruto notes that Kakashi is smarter than Shikamaru Nara, a better sense of smell than Kiba Inuzuka, a better taijutsu performance than Rock Lee, and has better Sharingan mastery than Sasuke Uchiha. Kakashi has proven himself to be an intelligent ninja with great instincts and battle prowess, making him a match for any opponent. His skills also improve between Part I and Part II: in Part I he has difficulty keeping up with Itachi Uchiha's speed, but by Part II he is able to match a clone of Itachi in combat despite it having only a portion of the original's strength. Similarly his chakra level has increased; in Part I he is only able to use the Lightning Cutter four times a day, but in Part II has been seen using it at least six times in one battle and still having enough chakra to plan on using the Mangekyō Sharingan. Kakashi is also able to summon a pack of ninja hounds to aid him in battle or for other supplementary purposes.
Kakashi's most distinguishing ability is his Sharingan, a gift from his late friend Obito Uchiha, as it allows him to copy nearly any technique used against him, see through any deception, give hypnotic suggestions, perform genjutsu, and predict his opponent's movements. However, because Kakashi is not of Uchiha blood, using the Sharingan demands a great deal of chakra. During the time skip, Kakashi further improved his Sharingan by developing his own Mangekyō Sharingan through undisclosed means. With it he can perform Kamui, a technique that sucks everything within a small area to another dimension.