Kakashi has been one of the most prominent figures in the Naruto series since the very beginning, and despite his prominence, the extent and origins of his power remain a mystery for the longest time.
With his mask and headband, Kakashi hides not only his appearance but also the Sharingan eye quite often during the show. When it’s revealed that Kakashi has a Sharingan eye, it’s a shock given that he isn’t a member of the Uchiha clan.
Traditionally, the Sharingan is limited to just members of the Uchiha bloodline, which the Keke Genkai stems from; however, Kakashi coming to boast this power came under unusual circumstances.
How did Kakashi get his Sharingan?
Kakashi received his Sharingan after suffering an injury as a child that resulted in him losing an eye. Shortly after this injury, Kakashi’s teammate Obito Uchiha was trapped under a boulder with no real chance of survival. While half of his body was crushed, he gifted his left eye to Kakashi to celebrate him making the rank of Jonin.
While Kakashi believed that Obito had died after being left for dead, we find out in Naruto Shippuden that he was saved by Madara Uchiha, who gave him the power of white Zetsu to repair his body and allow him to put the Akatsuki plan in motion.
Later in Naruto Shippuden, after doing battle against each other to save the world from Kaguya, Obito transfers his chakra to Kakashi, giving him a complete set of two Sharingan eyes with their own unique version of the Mangekyou Sharingan.
How did Kakashi lose his Sharingan?
While Kakashi did use the Mangekyou Sharingan in two eyes, this happened after he lost his one Sharingan eye, in fact, this is why it fades away entirely after his battle with Kaguya.
Madara tore Kakashi’s Sharingan eye out during their battle in the great ninja war. Naruto crafts a regular eye to replace this, but technically Kakashi would never get a Sharingan eye again after this. He was only able to use the abilities of this technique in battle thanks to Obito lending him his spirit and powers before passing on to the other side.
Because of this, Kakashi will likely never have access to the Sharingan again.
