The Sharingan, literally Copy Wheel Eye, is a very special condition of the eye that occurs naturally in some members of
the Uchiha Clan. While it is believed to have been derived from the Hyuuga clan Byakugan the abilities of the Sharingan differ
greatly from those of the Byakugan. Most notably the Sharingan's most well known ability is to be able to memorize any technique
that it has been a witness to including nijutsu, genjutsu and taijutsu techniques. Other abilities of this very special eye
include hypnosis, allowing it's user to suggest actions and thoughts to the opponent. The Sharingan also has the very useful
ability to see through any illusionary technique.
Just like the Byakugan, the Sharingan also has one main weakness, while it is not a blind spot as the Byakugan has, this
weakness could be more physically dangerous. When used for an extended period of time, in some cases, it drains the chakra
of the user quite quickly. Any user of the Sharingan must have a good amount of chakra and stamina in order to successfully
copy a technique, however, no amount of chakra will allow it's user to copy the abilities of another clans exclusive bloodline
abilities, or allow him to summon a creature with whom he has not made a contract with. Along with all these, the worst opponent
a Sharingan user could ever come up against is one who specializes in taijutsu such as Rock Lee. Because no hand seals involving
chakra are required for taijutsu they can not easily be copied unless the user has extraordinary amounts of strength, agility,
and stamina to keep up with the swift moves of a taijutsu user.
Unlike the Byakugan, the Uchiha clan Sharingan does
not appear automatically at birth in an Uchiha clan member. Instead the Sharingan will typically not show up until the user
is faced with a life threatening situation, the Sharingan will activate and help to save the life of the user, and after the
first appearance of the Sharingan, the user can call upon the use of the Sharingan at any time he pleases.
One interesting fact about the Sharingan is that you can gauge the power of the Sharingan user by counting the dots in
the person's eye. One dot would be a beginner, two an intermediate, and three dots are found in each eye of a matured adult
Sharingan user. It is not unusual to find a user whose two eyes contain different amount of dots, such as Uchiha Sasuke who
initially had two dots in one eye, and just a single dot in the other eye, until eventually both eyes evened out as he matured.
Users of the Sharingan include Uchiha Itachi, Uchiha Sasuke, Uchiha Obito (deceased), and Hatake Kakashi. Until revealed
in the Kakashi Gaiden storyline, it was always a mystery how Hataka Kakashi, not a member of the Uchiha clan, possessed the
Sharingan that is exclusive to the Uchiha clan.
We have learned that it is possible to transplant Sharingan eyes from one user to another, as is the case when Uchiha Obito
(team-mate of a young Hatake Kakashi) gifted his eye to Kakashi upon his own death, the implant was performed by Rin (team-mate
of Hatake Kakashi and Uchiha Obito). The drawback of being an un-natural user of the Sharingan is that it causes much more
strain on the body of the user, and unlike natural Sharingan users, they will never be able to achive the Mangekyou Sharingan
that far advanced users such as Uchiha Itachi possess.
The Mangekyou Sharingan (Kaleidoscope Copy Wheel Eye)
Mangekyou Sharingan, literally Kaleidoscope Copy Wheel Eye, is a higher form of the Uchiha clan Sharingan that is only achievable
by natural users of the Sharingan, those who have Uchiha blood running through their veins, eliminating Kakashi from potential
users. The Mangekyou Sharingan is not easy to obtain however for those who are not made of cold blood as they must make a
tremendous sacrifice in order to obtain it, they must kill their best friend.
To date only two people out of a possible three people have obtained this legendary eye, Uchiha Itachi and an unknown Uchiha
ancestor. The only other person who could possibly attain the Mangekyou Sharingan is Uchiha Sasuke, to obtain this he would
have to kill his best friend, presumably Uzumaki Naruto. With the Mangekyou Sharingan activated one major advantage is to
be able to use the three most powerful jutsu possible, two of which have been revealed so far: Tsukuyomi and Amaterasu.