Maito Gai

Guy is a tall and well-built man with high cheekbones, thick eyebrows, and black hair cut into a bowl-cut. He wears green jumpsuit, orange striped stockings, and a standard Konoha flak jacket, though he usually keeps it unbuttoned, having only done so during the Fourth Shinobi World War. His forehead protector, bearing the village's symbol, is sewn into red fabric and worn around his waist like a belt. As a genin, Guy wore a largely identical style of clothing, the only differences being the bandages on his arms and a maroon scarf around his neck.[7] His hair was also cut into a bowl-cut, though somewhat longer and curlier, framing the sides of his face. Upon becoming a chūnin, he began wearing the vest and removed the scarf.[8]

His protégé, Rock Lee, copied his master's clothing style, as the two bear a striking resemblance: the same naturally bushy eyebrows and the same haircut. Two years after the end of the Fourth Shinobi World War, Guy's appearance has remained virtually unchanged. His vest has been replaced by a simpler chest plate with high shoulder pads and a light green collar, and a bandage with a protector is attached to his waist, covering the vest. He wears a heavy cast on his right leg, likely due to injuries sustained during his battle with Madara, and also uses a red wheelchair for mobility.

Known for his bushy eyebrows, bowl cut, and green tracksuit, Guy often introduces himself as the "Noble Green Beast of Konoha" (木ノ葉の気高き碧い猛獣, Konoha no Keddaki Aoi Mōjū), a "dying species." Guy has many unique mannerisms throughout the series that seem rather corny and outdated, a reference to related clichés of "youth" (青春, seishun) in anime. Guy is also known for his rhetoric about the "Power of Youth." Guy has trouble remembering faces he doesn't often encounter, best demonstrated when he failed to recognize Kisame Hoshigaki twice, as well as in his battle with the Three Ryudoin Brothers and even in his fight against Madara Uchiha. Obito has mentioned this as one of Guy's characteristic traits.[10] This can be explained by the fact that Guy always looks to the future instead of dwelling on the past. Guy is also famous for his "good guy" pose, which consists of extending his right hand with an extended thumb and smiling brightly, followed by the proverbial "snap." This pose is often used by him and his favorite student, Lee, to indicate commitment to a statement they made previously, the ultimate form of promise. It is speculated that Guy got the idea for the "good guy" pose from his fight with Obito Uchiha during the Chūnin Exams. Despite his old-fashioned demeanor, Guy is capable of being decisive, serious, and sometimes even ruthless when necessary for the success of a mission, such as during the invasion of Konoha and in his battles with Kisame Hoshigaki. While typically absent-minded, Guy can at times be very attentive to a situation. During a diplomatic mission, Guy quickly deduced that its true purpose was a test of loyalty, an achievement that astonished even a young Itachi Uchiha.[11] During his battle with Kisame, he noted that while he adopted a serious demeanor, Kisame could appear quite intimidating, yet he remained extremely reliable.

Guy has good relationships with all of his teammates, but he's particularly interested in Rock Lee, who reminds him of his younger self, as both were considered failures and had to work hard to achieve their goals. In fact, Guy takes a greater interest in Lee's training than that of Neji Hyuga or Tenten, continuing to train him after the other two have retired. Because of this, and Lee's unwavering desire to hone his taijutsu skills, he and Lee have developed a father-son relationship, leading Guy to teach Lee several dangerous and forbidden techniques, but on the condition that he can only use them under specific circumstances. Although Guy is well aware of the risks of learning these techniques, he wants Lee to have the opportunity to prove himself as a great ninja and thus overlooks the consequences. Overall, however, Guy is a very caring and dedicated instructor, doing everything in his power to ensure his valuable students receive appropriate instruction in their specific fields. Guy, and therefore Lee as well, lives by his own philosophy of "Own Rules," which includes setting strict targets for failures so that something good can come out of them. For example, he promised to walk 500 laps around Konoha on his hands if he lost a simple game of rock-paper-scissors to Kakashi, and he still did so after his defeat, even if people eventually stopped paying attention to his behavior. Lee's willingness to train in the same manner as Guy seems to have driven him to surpass his teacher's stamina, and by the end of Part I, Guy was struggling to keep up with Lee, lamenting that he wasn't as young as he once was. During his early childhood, Guy's personality was diametrically opposed: he suffered from insecurity due to his lack of natural talent and was greatly concerned with the opinions of others.

The teacher-student relationship exemplified by Guy and Lee has many different attributes. For example, Guy beats Lee for the slightest infraction of the rules given to him. When Guy assigns him difficult training tasks to restore his focus and discipline, the two can break down in tears and finally embrace in a burst of sincere regret for the harsh blow he inflicted on Lee, although Tenten generally tolerates such antics and is more willing to participate in them than the more unyielding Neji.

Guy is a self-proclaimed rival of Kakashi Hatake, though the latter is usually indifferent to Guy's irritability in this regard. Since his first defeat against Kakashi in the Chūnin Exams, Guy has challenged him periodically and has achieved a record of 50 wins and 49 losses (50 wins and 51 losses in the anime). Given that the competitions that led to this figure are quite varied (from rock-paper-scissors to running races), this doesn't reflect Guy's actual accomplishments or an accurate comparison of their combat skills. Despite this fact, Guy is still proud of his record. Their competitions seem to stem from their contrasting personalities. Guy is much more easily agitated than the more laid-back Kakashi. He also relies primarily on taijutsu, unlike Kakashi's specialization in ninjutsu. He also worked tirelessly and for an extremely long time to reach Kakashi's level, while the latter's Sharingan and natural talent allowed him to improve more easily. Nevertheless, the two are great friends and have an immense trust in each other, as seen during the Fourth Shinobi World War, when the two watch each other's backs in battle. This was further developed in the anime, where Kakashi told Tsunade he would need a second-in-command and recommended Guy for the role.

The name "Might Guy" is a joke, referring to the "hot hero," an archetype that appears in many films and anime. Guy's appearance and demeanor appear to be based on those of Bruce Lee. He even uses nunchucks and wears a tracksuit. As of Chapter 595, Guy has all four animal directions of the Feng Shui compass associated with him: Morning Peacock is the Vermilion Bird, Midday Tiger is the White Tiger, his Ningame summon is the Black Tortoise, and his nunchaku design and aura when using Night Moth is the Azure Dragon. Moreover, all of his basic techniques correspond to the cycles of the day: morning, noon, evening, night. Studio Pierrot's Settei states that Guy's height was 143 cm in Naruto Shippūden the Movie: The Lost Tower and 170 cm during the Nine-Tails' attack. According to the Databook(s): Guy's hobby is repetition of exercises and training with boxing gloves. Guy wishes to fight Kakashi in a rematch. Guy's favorite foods are curried rice with strong spices and curried udon, but he believes it's impossible not to love food in and of itself. Gai's favorite phrase is "Overflowing youth!!" (Japanese: とび出せ青春!!, Tobidase seishun!!). Guy has completed a total of 788 official missions: 86 D-rank, 270 C-rank, 210 B-rank, 199 A-rank, and 23 S-rank. Oddly enough, while "ao" can mean both green and blue, most current subtitles and dubbing refer to Guy as the "Blue Beast" rather than the "Green Beast", yet in the manga it corresponds to the steam that surrounds him when the Eight Gates are released. In Naruto: Ultimate Ninja Heroes, Guy refers to himself as the "Magnificent Savage of the Leaf Village". In Episode 359 of the Naruto Shippuden anime, Guy states that he is an agnostic. Guy is afraid of ghosts and spirits.