Rock Lee (ロック・リー, Rokku Rī) is a chūnin-level shinobi from Konohagakure and the main protagonist of the series. Because he is unable to use any ninjutsu or genjutsu, he relies on taijutsu in his battles. He is a member of Team Guy along with Neji Hyūga and Tenten.
Rock Lee is is unable to perform any ninjutsu or genjutsu. As a result, he has been mocked by his peers since his time at the academy, though Might Guy took a special interest in him. When he graduated the academy, he joined Neji and Tenten as a member of Team Guy.
During his time as a genin, Lee along with his teammates, took the chūnin exams along with the Rookie Nine. In the preliminaries of the chūnin exams, Lee was matched up against the once cold heartless Gaara. Lee met his defeat after Gaara crushed his left arm and leg. His condition put his ninja work on hold, though Lee refused to quit training, though it made his wound worse. His condition was so bad, that a surgery performed by the worlds greatest medical ninja Tsunade only had a fifty percent chance of him survival. Tsunade encouraged him to forget about his dreams of becoming a ninja, but Lee after encouraging word from Guy, Lee decided to undergo the surgery anyways, unwilling to give up. When the surgery did take place, Lee survived, deeming it a success. Since then, he has continued his dream of becoming a splendid ninja without the use of ninjutsu or genjutsu.
Lee is extremely energetic, single-minded, and hot-blooded that unforturnately cannot utilize ninjutsu or genjutsu, so he solely works on improving his taijutsu, in which only requires physical exertion. He is also shown to be characterised as being the epitome of a "nice guy", having assumed many of Guy's personality quirks. He has a keen sense of honour, and respects his opponents, refusing to hold grudges against those who have defeated him. This was shown by his befriending of Gaara, forgiving him for crushing his arm and leg — injuries that nearly ended his career as a shinobi. Lee is incredibly determined to prove himself and had resorted to somewhat unorthodox antics to do so. Though he is unable to use any form of ninjutsu, Lee has resorted to make his own form of ninjutsu.
Lee's attempts to prove and better himself are recurring themes for his actions throughout the series. He is generally optimistic, and believes that, with hard work and passion, he can surpass a natural genius, but can be prone to depression when faced with setbacks. His drive to succeed was initially most evident with his rivalry with Neji. Neji, a "genius" ninja, found Lee's efforts of bettering himself to be in vain, and believed that Lee would be a "failure" for the rest of his life. Also, when making a promise, Lee assigns himself arduous tasks to complete in the event that he doesn't live up to his expectations. When this promise is broken, usually just barely, he trains to prevent it from happening again.
Lee is known for his somewhat insane antics, often scaring off onlookers, such as Tenten. He has a very intense personality, quick to challenge and battle. He also seems to be courageous and quite fearless, never hesitating to battle powerful opponents. Lee attempts to prove his strength to other people that are seen as more special than him, particularly those known as "genuises" like Neji or Gaara. This is shown when he challenges Neji and Guy to a duel and when he is set on proving that he has grown to Gaara.
Lee revealed that he liked Sakura Haruno, asking her to be his girlfriend and vowing to protect her. Sakura is often in his fantasies and skits. While she does not seem to share these feelings for him, and consideres him weird, Lee has maintained these feelings.
Lee is also seen to be a pervert, trying to peek on various occasions (normally Sakura). This was shown when Lee and Naruto tried to peek on Sakura in the bathhouse. Another was when he joined up with Jiraiya and his fellow male Konoha comrades to peek on Sakura and the other Konoha kunoichi.
Lee bears a Chinese-styled design along with the rest of the Team Guy. He is seen as almost an exact copy of Might Guy. Lee has rounded, black eyes with promenent lashes and bears considerably thick eyebrows which earns him a variety of nicknames such as Centipede Brows (ゲジマユ, Gejimayu; English TV "Bushy Brows"). His hair is styled in a bowl-cut fashion like Guy's and wears white bandages on his arms, which are also used in some of his jutsu. Lee's typical attire consists of a green jumpsuit, orange leg warmers, a standard Konoha flak jacket and a red forehead protector which he wears as a belt underneath it.
During his academy days, Lee's hair was much longer and fastened in a braid that, along with his style of dress, gave him a more traditional Chinese appearance. When Lee first joined Team Guy, Lee had shorter hair than before that curved upwards in the back, he maintained a Chinese appearance, since he wore a robe and a martial arts belt around his waist. After joining Might Guy's team, his appearance changed considerably to emulate his idol and sensei. After training under Might Guy, Lee cut his hair and styled into a bowl-cut style like Guy, and he still wears the same attire. The only difference is the absence of the flak jacket.
Lee is a shinobi who is only proficient in taijutsu, with no skill at all for ninjutsu or genjutsu, which is why he is infamously known as The Ninja Who Can't Use Ninjutsu (忍術の使えない忍者, Ninjutsu no Tsukaenai Ninja). Through Guy's leadership and Lee's hard-working resolve allowed Lee to improve rapidly. Lee has trained so extensively he can climb a building with three huge boulders strapped to his back and train himself to lift a 10 metric ton umbrella, and later 20, in a short amount of time. He is also capable of fighting off a group of missing-nin single-handedly.
Due to Lee's inability to use ninjutsu and genjutsu, Lee's dream is to become a famous ninja who uses only taijutsu. Taking a liking to Lee and his resolve, Might Guy trained him to reach this goal, teaching him a number of forbidden techniques in the process. The most basic of these is his Strong Fist style of combat, a martial art style focusing on external damage. His prowess surpasses those of more experienced ninja, able to keep up with Guy himself, and it is only in unique circumstances that his taijutsu is not enough to defeat an opponent.
Lee has a very low tolerance for alcohol, which gives him a natural predisposition for the Drunken Fist style. When he drinks or even smells the fumes of alcohol, he becomes an unpredictable and near unstoppable force of destruction and chaos. Guy explained that, after Lee accidentally drank a small amount of sake, he demolished an entire bar they were in. Lee's usage of this style gives him considerably greater speed and dexterity, allowing Lee to strike and effectively dodge from various positions. In the anime, it was shown that Lee can also go into this style of fighting by simply getting dizzy.
Through Guy's teachings, Lee has learned how to open six of the eight chakra gates and an incomplete seventh gate. By opening the eight chakra gates, Lee is able to make his muscles work more powerful then they were before, able to run at phenomenal speeds, pick up enormous weights, and much more at the cost of the muscles themselves. By developing a number of taijutsu he is able take advantage of the extreme power and speed he gains from opening chakra gates. Like his master, Lee can open the chakra gates instantly, even showing a faster recovery rate from using them without suffering any of the damaging after-effects, but he still shows noticeable exhaustion. In his fight with Guy, with the fifth gate activated, Lee was able to keep up with the taijutsu master despite opening the sixth gate. Lee can also open the limiters on his eyebrows to extend them outward. He can bind his opponents, use them as blades for his Rasenken, or spin rapidly to create whirlwinds.
His mastery of this skill also lets him utilise several kinjutsu derived from it. With the first gate, Lee can use the pile-driving Front Lotus and with the third gate, the more advanced Reverse Lotus. With the fifth gate, Lee can use the Morning Gorilla or the Morning Chicken, a counterpart technique of the Morning Peacock that uses the series of punches fast enough to set his hands ablaze by sheer speed and friction. With the incomplete version of the seventh gate, he can use the Infinite Lotus, a series of blazing punches and a single kick to the torso. The technique is powerful enough to leave Gaara exhausted and his armour severely damaged.
Despite not being able to use ninjutsu, Lee tries to create his own ninjutsu by using taijutsu or any other means to imitate other techniques and will eventually invent other pseudo-ninjutsu based off of the original. The only technique he seems to favor is Naruto's Sexy Technique.
Lee can also copy ninjutsu that includes nature transformations. By using materials or his taijutsu, he is able to generate his own nature. He is able to create wind by spinning rapidly fast, create fire by using matches, create lightning by rubbing a carpet around himself to create electricty, and create water by urinating.
Lee has also been shown to imitate a fake summoning technique. This is done by allowing Neji to put on a turtle costume to deceive his opponents. In the manga, Lee can also summon Neji's uncle, Hiashi Hyūga but never had a chance to work with him. 
Lee is also highly skilled in weaponry. His personal weapon of choice is the nunchaku, and from what has been shown he uses them with great speed indicating his proficiency.
Along with imitating ninjutsu, Lee creates his own form of genjutsu, basically performed by creating skits to give the illusion. His skits are sometimes used to help him with a situation rather than for battle. When used in battle, Lee is able to take advantage of the time his opponent is distracted by the skit to attack any support his opponent may have.