In the anime and manga series "Naruto," Naruto Uzumaki is on a quest to become the most powerful ninja in the land. Along the way, he fights alongside and against members of the Uchiha clan, ninja who fight with a special power called the "sharingan." The sharingan power utilizes the Uchiha ninja's eyes to create illusions and paralyze his opponents. The mangekyou sharingan is a high-powered form of the sharingan that only a few ninja obtain – most notably, Sasuke's brother Itachi Uchiha. Only the fictional characters in the world of "Naruto" – and only some of these characters – can obtain the mangekyou sharingan.
The Natural Method
Be born as an Uchiha. To qualify for the mangekyou sharingan naturally, you must have Uchiha blood in your veins, although not all Uchiha have this power. Before "Naruto" begins, Itachi Uchiha kills most members of his clan, which leaves only Itachi, his younger brother Sasuke and their immortal ancestor Madara Uchiha alive. After "Naruto" begins, they are the only ninja who can naturally develop the mangekyou sharingan.
Level up your sharingan eye to "three commas." The natural sharingan possesses three levels of mastery: "one comma," "two commas" and "three commas." The number of commas refers to the number of comma shapes that appear in the red eyes when the ninja activates the sharingan. The more you use the sharingan, the more powerful it will become. You can only achieve "three commas" after you can use ninjutsu (ninja techniques), taijutsu (martial arts) and genjutsu (illusory techniques).
Make a tremendous sacrifice. According to Itachi in the "Naruto" series, the "tremendous sacrifice" the ninja must make in order to evolve his sharingan is to destroy his best friend and feel great sadness.
The Unnatural Way
Replace your eye with an Uchiha's eye via ninjutsu. Kakashi Hatake, Naruto's team leader, is the only non-Uchiha to possess the sharingan, although he can only use the technique in one eye. Kakashi lost his eye in battle. His dying friend, an Uchiha with the sharingan, told Kakashi to replace his lost eye with his own sharingan eye. With the help of ninja ninjutsu, Kakashi implanted his friend's eye into his own socket on the battlefield.
Practice the use of the sharingan eye. Once you've magically attached your eye with ninjutsu, train until you have better control over your sharingan. You may have to evolve the sharingan to two or three commas, unless the previous owner already evolved the eye.
Mysteriously evolve the eye to mangekyou sharingan. Kakashi is the only known non-Uchiha ninja in "Naruto" to have the sharingan. He evolved his own form of the mangekyou sharingan. Kakashi has never revealed how he evolved this form and whether or not he made a tremendous sacrifice to obtain it. However, he is a good ninja, and he likely did not destroy a friend.
When leveling up your sharingan, one eye may level up faster than the other.
If you want to "obtain the mangekyou sharingan" in real life while roleplaying, purchase red contacts, preferably with kaleidoscope black lines.
The mangekyou sharingan does not exist in real life.
Three of the ninja who achieved the mangekyou sharingan – Itachi, Sasuke and Madara – killed people about whom they care to achieve this skill. The mangekyou sharingan can be an evil technique.
Consistent use of the magekyou sharingan leads the eyes to degenerate. Eventually, the user could become blind.