Guy is a tall and well-built man with high cheek-bones, thick eyebrows and black hair cut in a bowl style. Guy wears a green jumpsuit, orange-striped leg warmers and the standard Hidden Leaf flak jacket which is unzipped. His forehead protector, is on a red cloth and is worn around his waist, like a belt, and also wear black sandals.
Known for his thick eyebrows, green jumpsuit, and shiny bowl haircut, Guy often refers to himself as "The Leaf's Noble Gentleman". He has many mannerisms unique to him in the series that are meant to be seen as corny and old-fashioned, a reference to common clichés of "youth". Guy is also known for going on about the "Power of Youth". Guy has problems remembering the faces of persons he does not interact with frequently, best seen in his fights with Kisame Hoshigaki, and his fight with the Three Ryudoin Brothers. Obito has mentioned this as a trait of Guy's. It was explained that this may be due to the fact that Guy always looks to the future instead of dwelling in the past.
Guy is best known for his "nice guy pose", which consists of giving a thumbs up, winking, and smiling with teeth so white they give the proverbial "ping". This action is often used by both Guy and Lee to indicate commitment to a statement they had just made, their highest form of a promise. It is suggested that Guy got the idea for the "nice guy" pose from his battle with Obito Uchiha during the Chunin Exams. Despite these odd mannerisms, Guy has shown to be capable of being as serious, ruthless and decisive as a mission's success demands if needed, as seen during the Invasion of the Hidden Leaf and his battles with Kisame Hoshigaki. Despite his seemingly oblivious nature at time, Guy can be very attentive to the situation at hand. During a mission of diplomacy, Guy was able to deduce its true purpose as a test of loyalty, a feat which astounded a young Itachi Uchiha. He is noted to be quite scary if switching to "serious", but very reliable.
Guy is on good terms with all of his students, but takes particular interest in Rock Lee, who reminds Guy of himself in his youth in retrospect that both are considered losers and have to work hard to achieve their goals. As such, Guy puts much more interest in Lee's training than Neji's or Tenten's, continuing to train Lee long after the others have retired for the day. Because of this, and due to Lee's unyielding desire to master the art of taijutsu, the two have developed a father-son relation that has pushed Guy to teach Lee a number of dangerous and forbidden techniques, giving the stipulation that Lee can only use them under specific circumstances. Although Guy knows of the dangers that teaching the techniques to Lee entails, Guy wishes for Lee to be able to prove himself to be a splendid ninja, and, as such, turns a blind eye to the repercussions. However, overall, Guy is a very attentive and dedicated instructor, who does everything in his power to make sure that all three of his prized students receive proper instruction in their own particular fields.
Guy, and, by extension Lee, lives his life by his own "My Rules" philosophy, which involves setting tougher goals for failure so something good comes of it. For example, he vowed to walk 500 laps around Konoha on his hands if he lost a simple game of rock, paper, scissors with Kakashi, and proceeded to do so upon losing, even though people stopped paying attention eventually. Lee's willingness to train in the same manner as Guy seems to have caused him to surpass his master's stamina, as by the end of Part I, Guy has difficulty keeping up with Lee, lamenting that he is not as youthful as he once was. During his early childhood, Guy's personality was quite the opposite; he suffered much insecurity from his lack of natural talent and was greatly concerned about other people's opinions.
Guy's teacher-student relationship with Lee also carries distinct attributes, such as when Guy will punch Lee for a slight infraction of a rule. After Guy assigns Lee an arduous training task as punishment, meant to recapture Lee's focus and discipline, the two may then burst into tears and affectionately embrace, in brief regret for the strong blow Lee was given. Guy often attempts to act in a similar way towards his other two students, although Tenten is usually resigned and more willing to take part in his antics than the more stoic Neji.
Guy is the self-proclaimed rival of Kakashi Hatake, though the latter is indifferent to the former's annoyance. Since first losing to Kakashi during the Chunin Exams, Guy randomly challenges Kakashi to contests of skill, and has acquired a record of 50 wins and 49 losses in doing so (50 wins and 51 losses in the anime). Given that the contests that make up this figure are so varied (ranging from Rock, Paper, Scissors to running races), this is not much of an achievement on Guy's part nor an accurate comparison of respective combat power. Nevertheless, Guy is proud of his record. Their competitions seem to, in part, be founded on the fact that the two are polar opposites. Guy has shown to be more easily excited compared to the more laid back Kakashi. He also relies mainly on taijutsu, in contrast to Kakashi's ninjutsu specialisation, and had to work tremendously hard to reach his level of prowess, whereas Kakashi's natural talent and Sharingan made it easier for him to improve. Nevertheless, both men are great friends and also have the utmost faith in each other seen during the Fourth Shinobi World War when they entrusted the protection of their blind spots to each other. This was also expanded on in the Naruto anime, where Kakashi told Tsunade that he would need a second-in-command during the war and wanted Guy to serve that purpose. Guy's and Kakashi's level of friendship was such that when faced with five fully transformed tailed beasts preparing to fire their Tailed Beast Bomb in close proximity.
Guy can't handle sea rides and easily gets seasick when he has to travel by boat or ship. After getting over this and attempting the challenge at the Falls of Truth, Guy's "inner self" rebuked him for being too old yet still maintaining a hyper-active demeanor, adding that it is not healthy for old men like him to push themselves so hard. In the Naruto anime, he also described himself to be an agnostic.
Taijutsu Master: During childhood, Might Guy had a very low talent in ninjutsu and genjutsu, so he focused tremendously on taijutsu like his father. Might Duy saw this as an opportunity to teach him his own strengths and weaknesses. This in turn gave Guy a chance to focus on his own "virtues" that other kids of his age could not do, ultimately becoming more proficient than most adult shinobi in the art. As an adult himself, Might Guy is an extremely accomplished taijutsu master, with advanced knowledge, if not skill, in various taijutsu styles and techniques, able to immediately recognize one he witnesses. As noted by Kisame Hoshigaki, it is very rare for one to reach Guy's level of prowess. Through his "One's Own Rule" philosophy, which involves a series of extreme and unorthodox training regimes, Guy has obtained peak physical conditioning and prowess, becoming highly enduring with immense reserves of chakra and stamina. This allows him to recover from extreme exhaustion in an alarmingly short period of time and utilize the style known as "Strong Fist" to its full potential without wearing himself down.
- Immense Speed and Reflexes: In addition to his "One's Own Rule" philosophy, Guy has gained such tremendous speed, seeming like he's disappearing to unfocused eyes.
- Immense Strength: Guy possesses unparalleled strength and able to easily ploughing a full-grown man through a solid stone wall and into the air with a single hand: accomplishing both feats without the aid of chakra-enhancement. His strength could also easily repel Gaara's sand attack in Part I.
- Immense Endurance: Because of his hardwork and developing his own philosophy, Guy shows tremendous endurance and stamina, able to remain active for at least a full day without exhaustion.
- Enhanced Durability:
Eight Gates: Guy is able to utilize and open all of the Eight Gates, a feat he mastered while still a child. This portrays Guy's prowess as most ninja, even with natural talent, are unable to open even a single gate. His knowledge and understanding of this ability allowed Guy to instantly open from any individual to all of the first seven gates and to teach others to access the gates. Because of the potential harm opening the gates can cause the user, Guy has decided that he will only open the gates if it is a life-or-death situation, or he is protecting someone dear to him. However, Guy's extremely intense training routines has allowed him to handle opening the gates for longer periods of time, able to endure the sixth gate with only noticeable exhaustion, as well as resist the after-effects of the seventh gate to continue fighting for a short period. By the Fourth Great Shinobi War, Guy became able to withstand using the seventh gate repeatedly with only momentary exhaustion. His mastery of this skill also lets utilise him several kinjutsu derived from it. With the first gate, Guy can use the pile-driving Primary Lotus and with the third gate, the more advanced Hidden Lotus. With the sixth gate, Guy can use the Morning Peacock, a series of punches so fast that his hands were set ablaze by sheer speed and friction. With the seventh gate, he can use the one-hit kill Daytime Tiger, which is strong enough to completely overwhelm Madara Uchiha's Perfect Susano'o and completely subdue Kisame Hoshigaki to near immobility.
Bukijutsu Expert: Guy is also highly skilled in a variety of weapons styles, having trained Tenten extensively in their respective usages. His personal weapon of choice is the nunchaku, but only resorts to using them against especially strong enemies. He has shown to use this weapon with great ferocity and power, matching Kisame's unique swordplay. Aside from his regular set, Guy keeps a special pair of nunchaku called the Soshuga, which he used to skilfully battle Obito. These were durable enough to smash a large rock into pieces, and trade blows with Obito's gunbai.
- Team Guy
- Kakashi Hatake (Childhood best friend and Arch-rival)
- Naruto Uzumaki
- Hidden Leaf 11
- Aoba Yamashiro
- Kakashi Hatake (Arch-rival)
- Ryuha Armament Alliance
- Madara Uchiha
- Obito Uchiha (Former classmate)
- The Ten-Tails
- The Akatsuki
- Hidden Sound Village