Young Kakashi Hatake

Kakashi was the son of the legendary White Fang of Konoha, Sakumo Hatake, and like him was considered a gifted shinobi. He graduated from the academy at the age of 5, becoming a Chunin a year later. However, his success came at a great loss; his father, once well respected in the village, fell into disgrace after choosing to save his comrades rather than complete a mission, causing Konohagakure to suffer in the war effort. Dishonored, Sakumo committed seppuku after deep depression and a drop in his skills, which caused Kakashi to lead his life strictly by the Ninja code. His White Light Chakra Saber, for which his father was nicknamed, was given to Kakashi.

He went on to become apart of the Team Minato, led by the future Fourth Hokage, Minato Namikaze, with Obito Uchiha and Rin, a medic-nin. Kakashi's relationship with Obito and Rin was very much similar to that of Sasuke's relationship with Naruto and Sakura respectively in which they share a complicated relationship that later developed into a close friendship.

In the midst of the Third Great Shinobi War, at a meeting to hear their new mission, Kakashi was elevated to Jonin and received gifts from his teacher and teammates; A special kunai from Minato and a medical pack from Rin. After receiving their gifts, the Fourth informs the team of their mission: they must travel through the Grass Country in the midst of a conflict between Iwagakure and Konohagakure to destroy a bridge. Along the way, Kakashi’s team notices that they’re being watched from the trees by Mahiru, an Iwagakure ninja. Kakashi sees this as a good opportunity to use his newly created jutsu, the Chidori. He arrogantly ran off to attack the hidden foe, only to face off against Mahiri’s multiple Shadow Clones while Rin was captured by enemy Shinobi. Obito immediately stated his intention to rescue her, but Kakashi disagreed on the basis that they needed to complete their mission, opting not make the same mistake his father did. Kakashi parted ways with Obito soon after, and as he reflected on Obito’s words and Rin’s prior kindness, he realized that his father had made the right choice after all. This prompted him to rejoin Obito in the rescue effort, claiming that Obito couldn’t survive on his own.

During the attempt to rescue Rin, Kakashi detected a Rock ninja, and yelled a warning to Obito, who was too slow to react. Kakashi jumped in front of Obito to save him from the enemy's kunai, losing his left eye in the attack. Obito, in return, awakened his Sharingan and killed their assailant. The two managed to rescue Rin, however, a rockfall technique was triggered, hindering their escape. It was then that Obito chose to make the ultimate sacrifice, pushing Kakashi out of its path. As he laid there dying, Obito had Rin implant his Sharingan eye in Kakashi’s damaged eye socket, referring to it as a gift. He died shortly thereafter. As his first act with his new eye, Kakashi avenged Obito by killing the enemy ninja with his now-perfected Chidori technique. Obito's death had a huge impact on Kakashi's personality; initially flaky and unreliable, Kakashi became more mellow, having adopted some of Obito's traits such as his notion for teamwork

Details

Kakashi became a Chunin at age 6, and became a Jonin at age 13. The fourth hokage was in charge of Kakashi's team. The scar on Kakashi's left eye came from a battle with the rock ninja. Kakashi jumped in front of Obito to save him from the enemy's kunai, and thus Kakashi ends up with the scar.

Obito's sharigan eye only had two stages when he gave it to Kakashi. Kakashi's sharigan eye has three stages, showing that Kakashi has evolved it into its third stage