Kakashi is the Konohagakure Jonin assigned in the beginning of the manga and anime
Naruto to train and look after Team 7: Uzumaki Naruto, Uchiha Sasuke, and Haruno
Sakura. He is also known as Copy Ninja Kakashi or Kakashi of the Sharingan.These
aliases refer to the fact he copied more than a thousand jutsu (ninja techniques)
using his left eye, which possesses the Sharingan, an advanced bloodline trait
found only in some members of the nearly defunct Uchiha clan. The three dots (tomoe)
in the pupil of his Sharingan-activated eye indicate that it is fully developed
for a normal Sharingan, with only one more level: Mangekyo Sharingan. .Chronically
tardy, Kakashi initially appears to be flaky and unreliable. He is, however, one
of the strongest and most skilled Jonin in the village of Konoha, a child prodigy
who attained Chunin rank at the age of 6 and became a Jonin at age 13. Hatake
Sakumo, Kakashi’s father, also known as Konoha's White Fang, was a genius
ninja on par with the legendary sannins. He abandoned an important mission to
save his comrades, after which he was blamed and disgraced even by those he saved;
and thus committed suicide. Kakashi was about 8 years old when he bore witness
to this tragedy. After his father’s suicide, Kakashi started to adhere strictly
to the shinobi rules, in particular, the rule dictating that the mission must
come first. He became arrogant, humorless, and by-the-book. Kakashi achieved Jonin
status at 13 years of age. There was no elaborate ceremony. Instead his reward
was to lead his team on a sabotage mission to blow up a bridge in order to prevent
forces from Earth Country from entering Grass Country. He graduated the academy
at 5 which means he probably entered it at 4. He started wearing a mask as a child
and continues to wear it as an adult. Kakashi lost his left eye while protecting
Obito and his scar is a result of that injury. They were able to rescue Rin, but
were again attacked by the enemy whereupon Obito sacrificed himself to save Kakashi.
Upon his death, Obito bequested his left eye to Kakashi to replace the one he
had lost. This mission, in which he got his distinctive eye and learned the lessons
about teamwork and friendship that he tries to instill in Naruto and Sasuke, that
fundamentally created Kakashi's character. Even his character's chronic lateness
commonly used for comedic relief since it clashes with the seriousness of a ninja,
were revealed to stem from long periods of reflection at Obito's memorial.