Kakashi Hatake is a beloved character in the animanga world of Naruto created by Mashashi Kishimoto. He is a fundamental character in the anime and the manga and is still in the sequel to Naruto, Boruto:Next Generations for this reason. He’s potentially one of the most powerful characters in the series for his unique abilities.
The main reason Kakashi was such a celebrated ninja within the whole Naruto world, but specifically Konohagakure (the Hidden Leaf Village in the English Dub) is his ownership of the Sharingan.
As a result of owning this visual jutsu Kakashi earned the colloquial title of ‘Kakashi the Copy Ninja’. In the manga, the first time we actually see the Sharingan, and the first time Kakashi reveals his own Sharingan, is in Chapter 12 when Kakashi uses his Sharingan to defeat Zabuza of the Hidden Mist.
As a result of owning the Sharingan Kakashi has copied almost all of the jutsu (at least the ones he can copy without having a kekkei genkai) present in Naruto and this makes him a formidable foe.
However, the Sharingan is actually a kekkei genkai of the Uchiha clan, Kakashi is one very few people who actually owns a sharingan without being part of the clan.
In the rest of the article we will explore why Kakashi has a Sharingan and ultimately why this means he must hide it under his headband, the answer is quite complex.

Firstly, What Is The Sharingan?
The Sharingan eye is one of the most important eyes and kekkei genkai in all of Naruto. At a basic level, you have to be born into the Uchiha clan in order to have the potential to awaken the Sharingan in the first place.
However, as evidenced by Kakashi, there are ways to obtain the Sharingan without being part of the Uchiha clan.
Perhaps the most notable ability of the Sharingan is to copy another shinobi’s jutsu when in battle, which is a pretty overpowered visual prowess for this reason. There are other abilities such as being able to see chakra as well as a host of others we won’t get into right now.
However, there are multiple levels to the Sharingan eye that can be awakened. Even when born into the Uchiha clan, the Uchiha member still has to ‘awaken’ the Sharingan in order to use its base form, not all Uchiha members will awaken the Sharingan as a result.
In Kakashi’s case he didn’t awaken the Sharingan, rather, he was gifted it.
In any case, to awaken a Sharingan eye the Uchiha member must go through some form of strong motion in order to awaken it, there isn’t a specific emotion that will awaken it, it can be any sort of emotion as long as it is experienced strongly.
For instance, Sasuke awakens his sharingan when his clan is wiped out by his brother Itachi – more on that later.
However, Kakashi does have the second level of the Sharingan eye which is known as the Mangekyou sharingan, we can tell this visually by the three tomoe present in Kakashi’s Sharingan, rather than two which is the base form of the Sharingan.
He did awaken his Mangekyou sharingan when he accidentally killed Rin Nohara, as did Obito even though Obito was basically on his deathbed after being crushed by the rock that killed him.
How Did Kakashi Get The Sharingan?
As mentioned, one the only ways to get the Sharingan is to be born into the Uchiha clan. However, characters such as Danzo and Kakashi have the Sharingan because they were gifted it, or they stole it in Danzo’s case.
A medical-nin must be present in order to complete the eye transplant, or at least a shinobi with the power to do so.
Without going into too much detail, Kakashi was given the Sharingan by his former teammate Obito Uchiha. Obito Uchiha was Kakashi’s teammate alongside Rin Nohara, their sensei was Naruto’s father, Minato Namikaze.
Obito is crushed by a rock during a mission and ‘dies’, although his dying wish is to gift his Sharingan to Kakashi. Rin Nohara, the medical-nin in their team was able to enact the transplant there and then thanks to her medical abilities. Soon after, Kakashi awakens the Mangekyou Sharingan.
So Why Does Kakashi Hide The Sharingan Under His Headband?
There are two reasons why Kakashi hides his Sharingan.
Firstly, the transplanting of the Sharingan eye is not without its disadvantages. If the eye has been transplanted to someone not of the Uchiha clan there are drawbacks, namely that their body is not made to host the Sharingan.
As a result, the Sharingan uses a lot of its non-native host’s chakra. Put simply, Kakashi cannot use his eye to the same extent that Obito or another member of the Uchiha clan would be able to as he is not of the Uchiha clan.
Danzo could only utilise his many stolen Sharingan eyes because he had transplanted Hashirama’s cells into himself as well, although that’s another topic altogether.
Another disadvantage of having the eye transplanted into a non-Uchiha is that they cannot close the eye that the Sharingan has been transplanted to, or moreover, he cannot turn it off. An Uchiha member can turn their Sharingan on and off at command, Kakashi cannot. This is the same reason why Danzo has his eye covered.
Secondly, you need to understand that during the first chapters of Naruto, Sasuke is the only member of the Uchiha clan left (technically he isn’t, but the audience and the inhabitants of Konohagakure don’t know this yet).
The citizens of Konohagakure are aware that the Uchiha clan, one of the founding clans of the village, was wiped out by one of their own members, Sasuke’s brother, Itachi Uchiha.
So, anything to do with the clan is fairly taboo within the village during that time hence why Sasuke is such an outsider, like Naruto.
Even though most of the shinobi who regularly take part in missions are aware that Kakashi has a Sharingan, as he uses it often in battle, they don’t know how he obtained it, nor do the villagers know he has it.
As a result, Kakashi doesn’t really show it off that much, unless in battle, so as not to raise any concerns among the villagers and stir up rumours.
Conclusion
So, there you go. Kakashi hides his Sharingan under his headband as he cannot turn his Sharingan off, one of the many potential disadvantages of transplanting the Sharingan into a shinobi who is not a member of the Uchiha clan. Danzo covers his eye for the same reason.
Although, both Danzo and Kakashi wouldn’t show it off anyway so as to not worry the villagers who are wary of the Uchiha clan after the clan’s downfall.