Obito Uchiha

was a former team-mate and friend of Kakashi Hatake and a member of Team Minato who appeared in the Kakashi Gaiden arc.

Background
Obito graduated from the Ninja Academy at the age of 9, and was promoted to Chūnin at the age of 11. During the Third Great Shinobi World War, Team Minato was assigned the task of destroying the Kannabi Bridge. Because Kakashi had recently been promoted to Jōnin, he was to be left in charge of the mission. Before setting out, however, Minato Namikaze and Rin gave Kakashi gifts, something Obito forgot to do. Minato left them to go fight on the front lines, and Rin was soon captured by Iwagakure forces. Kakashi chose not to go save her, placing the mission's completion first, but Obito refused to comply, stating that, while those who break the rules are scum, those who abandon their friends are worse than scum. After that, they parted ways.

When Obito found where Rin was being held, he was immediately attacked by Taiseki. Kakashi, having had a change of heart, arrived in time to save Obito, while Taiseki used the Hiding with Camouflage Technique to disappear. Invisible, Taiseki was able to damage Kakashi's left eye. To save his team-mate, Obito awakened his Sharingan, immediately proving proficient enough with it to locate and kill Taiseki. Obito and Kakashi went to defeat Kakkō and save Rin, but once she was freed, Kakkō started an enemy-induced cave-in and escaped.

When Obito pushed Kakashi out of the way of a falling rock, his right side was crushed. Unable to free himself, Obito asked Rin to give Kakashi his remaining Sharingan, to make up for not giving him a gift earlier. Once the eye transfer procedure was complete, Kakashi moved forward to kill Kakkō with a perfected Chidori.

Sensing that reinforcements from Iwagakure have arrived and attacked them (causing the cave to collapse once more), he forced Kakashi and Rin to leave him in the collapsing cave. Obito was then crushed by the falling boulders while he was thinking about his two team-mates, sadly remarking how he was unable to fully deepen his friendship with both of them when they were already getting along well.

Personality
Obito was constantly tardy, always claiming he had been doing a good deed, such as helping an elderly woman carry her luggage. Minato referred to this as the truth, though Kakashi didn't believe him. Obito was also a little stubborn at times, yet, unlike Kakashi, who was very strict of the rules and regulations, he was usually carefree, and would rather save a team-mate than complete a mission - the same as Kakashi's father, Sakumo Hatake. Obito would also lie to get out of trouble or just an uncomfortable situation - whenever he would start crying, he would claim he had something in his eye, though usually at the time he had his goggles on. Obito had romantic feelings for his female team-mate Rin, though he never revealed them to her, not even when he was dying.

Obito has similar thin facial structure to Naruto Uzumaki, and they both also have similar personalities. Both were desperate to get attention as a child, they both have a rivalry with their other male team-mate (Sasuke Uchiha for Naruto and Kakashi for Obito), and they both have romantic feelings toward their female team-mate (Sakura Haruno for Naruto and Rin for Obito). They were also considered "goofballs" or "knuckleheads" because of their recklessness. Unlike Naruto, however, Obito seems to be more conserved, not screaming out or recklessly challenging unless forced.

Abilities
As a member of the Uchiha clan, Obito could use Fire Release jutsu, which he was able to use quickly, as seen in his fight with two Iwagakure ninja where he demonstrated quick usage of the Fire Release: Great Fireball Technique and was also able to incinerate a trap that was set by enemy ninjas. He was also able to awaken his Sharingan and immediately use it with great ease, despite it being his first time using it. He displayed fast reflexes and good taijutsu skill, which, together with his Sharingan and Kakashi's help, was proven an effective fighting combination.

Trivia

 * Obito's first appearance in the anime is actually in Part I of Episode 72 in a flashback of the Third Hokage.
 * In a brief flashback that occurs during Kakashi's near-death experience at the time of Pain's invasion of Konoha, Obito's left Sharingan eye is erroneously depicted as having three tomoe instead of two.

Quotes

 * (To Kakashi) "I am Uchiha Obito and I will surpass you once I awaken my Sharingan!"
 * (To Kakashi) "Those that break the rules and regulations are scum. But those who abandon their comrades are worse than scum. If I'm going to be called scum either way, I'd rather break the rules! And if that's not being a proper shinobi, then I'll destroy that idea!"
 * (To Kakashi) "I believe the 'White Fang' is a true hero!"
 * (To Kakashi) "I'm about to... die... but I'll become your eye."
 * (Last words) "Just when me and Kakashi were becoming friends... I couldn't bring myself to confess to Rin... I wish I had more time with everyone..."