Might Guy

is a jōnin of Konohagakure. A master of taijutsu, Guy leads and passes his wisdom to the members of Team Guy.

Background
Guy is the son of Might Duy, who was known throughout Konoha as the "Eternal Genin". Duy was not bothered by this moniker and instead was grateful that other people cared enough to know him at all. Duy encouraged this same kind of optimism in Guy, as well as his belief that one always has youth and that they could both become taijutsu masters through diligent training. Guy did his best to embody his father's teachings, but had doubts that Duy's words were devoid of meaning. He nevertheless loved his father and fought others when they called Duy the "Eternal Genin" mockingly; when one of these fights landed him in the Konoha Hospital, Duy encouraged Guy not to be upset by this loss and to instead remember that victory is achieved by defending things that are important.

Guy applied to enter Konoha's Ninja Academy, but did not pass the entrance exam. Kakashi Hatake was not surprised due to Guy's lack of talent in ninjutsu and genjutsu, which Guy chose to take as a supportive observation. This strength of character convinced Kakashi's father, Sakumo, that Guy was not handicapped by his shortcomings and that he might be offered a position as an alternate in the year's Academy class. Guy was indeed allowed to enter the Academy with Kakashi, and upon graduation he was added to a team that, in the anime, was led by Chōza Akimichi. The team at one point entered Konoha's Chūnin Exams and passed to the final stage; Guy himself advanced to the exams' last one-on-one match, where he lost to Kakashi. While on a mission during the Third Shinobi World War, Guy and his team were attacked by the Seven Swordsmen of Kirigakure. They were rescued by Duy, who used the Eight Gates Released Formation to fight off the Seven Swordsmen. Duy died from opening all Eight Gates, but it satisfied his one rule for its use: giving his life to protect something precious, namely Guy.

Guy at some point decided that Kakashi was his lifelong rival, driven by a desire to prove his perseverance could be just as good as Kakashi's natural genius. He would constantly challenge Kakashi to contests of skill, from eating contests to Rock, Paper, Scissors. Kakashi was indifferent to these contests, which only fueled Guy's desire to defeat him. In the anime, Kakashi prevailed in the earlier of these competitions, but Guy soon started catching up, eventually achieving only a one point difference in their scores that has remained consistent over the years. Guy is proud of his score despite the fact that, because of how varied the contests are, it is hardly representative of anything. Through their competition, Kakashi and Guy became good friends; they were hanging out together on the night of the Nine-Tails' attack on Konoha, yet were prevented from helping defend the village, instead being confined within a barrier to keep them safe.

In the anime, Guy was aware of the losses Kakashi experienced during and after the Third Shinobi World War and tried to help him deal with them. Following the death of Obito Uchiha, Guy filled in for Obito while Team Minato was on a mission into Iwa-territory. When they were surrounded, Guy tried giving his life to allow Kakashi to escape, but they were able to fight off their enemies until reinforcements arrived. Following the death of Rin Nohara, Kakashi's teacher, the Fourth Hokage, sent Guy to tail Kakashi on a mission in case memories of Rin started to get to him. This proved wise: when Kakashi began hyperventilating from using the Chidori - the same jutsu that killed Rin - Guy intervened in time to save Kakashi and take him home. Following the Fourth's death during the Nine-Tails' attack, Guy requested to be admitted into the Anbu so that he could help Kakashi through his growing depression. The Third Hokage refused his request, which Danzō Shimura seconded, explaining that Guy lacked the necessary darkness for Anbu-service. Guy witnessed this "darkness" when Kakashi provided backup for him during a meeting with the Land of Woods, wherein Kakashi mercilessly killed all the Land of Woods' forces. Guy asked the Third Hokage to remove Kakashi from the Anbu because these kind of acts didn't become him. When the Third eventually complied, Guy suggested that Kakashi try leading a team of genin to help him regain his lost kindness.

Guy at some point heard about a boy in the Academy who was unable to use ninjutsu or genjutsu. Guy approached this boy, Rock Lee, and encouraged him to use his youth to keep training. Lee was eventually added to Guy's Team Guy, along with Neji Hyūga and Tenten; in the anime, before accepting them, he required them all to demonstrate a desire to succeed no matter the odds. Guy took a particular interest in Lee after the team's first meeting, as Lee wished to become a splendid ninja who could only use taijutsu. Guy decided to dedicate his life to helping Lee achieve his dream, teaching him all he knew of taijutsu, telling him the same keys to self-improvement his father had taught him, and encouraging him to use a rivalry with Neji to push him to new heights. Lee developed well under his guidance, as did Neji and Tenten, though Guy felt it was best to have them wait a year before entering the Chūnin Exams.

Personality
Guy is perhaps most fully represented by his "nice guy" pose: a thumbs up, wink, and winning smile - complete with the proverbial ping. The pose captures his optimism and confidence, as by striking the pose he is promising that whatever words accompany it are either true now or will become true in time. It represents his energy, as he will, through his understood-only-to-himself-and-select-others "Power of ", enthusiastically seek to live up to his promise no matter the personal investment doing so will require of him. It plumbs his deep emotional well because he only reserves it for the most important promises to the most important people for the most important reasons, and as such tears frequently stream down the face of somebody (inevitably Guy) when the pose is struck.

Guy can be serious at times despite his odd mannerisms, usually when engaging an enemy who threatens Konoha or one of his comrades. But even his serious moments can be undermined by one of his eccentricities: Guy has faced Kisame Hoshigaki on three separate occasions, yet on each occasion he's been fairly confident that he never met Kisame before - Guy is aware that he has a poor memory for faces, which is suggested to be because he always looks to the future instead of dwelling in the past; from observing the vibrancy of youth that his students possess, Guy may, in a moment of thoughtful self-reflection, wonder if his own youth has passed him by, only to immediately dismiss this as impossible because youth can never fade; if his student, Lee, should break one of his tenets of conduct, Guy will discipline him with a physical strike, only to then immediately start crying at the realization of the harm he's inflicted and the well-intentioned passion that led Lee astray in the first place.

Guy refers to himself as. Like many of Guy's traits, the moniker may be fitting. Lee wholeheartedly approves of Guy, modeling his own appearance and personality after Guy's so that he can become as beautiful a man as Guy is. For these similarities and their common backgrounds, Guy is in turn dedicated to Lee, doing all in his power to help Lee achieve his dream of becoming a master of taijutsu. Their almost father-son bond is so powerful as to sometimes be disturbing to others; Neji and Tenten, though they also benefit from Guy's teachings, are only willing to join in on Guy and Lee's antics up to a point, and will either rein them in or leave them to their devices if their patience has been exhausted. Kakashi shares Neji and Tenten's reservations with Guy, and is often only an unwilling or indifferent participant in their contests. Rather than discourage Guy, this further motivates him, as he wants to defeat Kakashi's "cool, hip, and trendy" personality. There is no animosity to their rivalry, however, and Kakashi in fact considers Guy to be one of his closest and most reliable friends: they work well together in the field, can understand what the other is thinking without anything being said, and are concerned for each other's well-being.

Appearance
Guy has a shiny bowl style hair cut and remarkably thick eyebrows; Naruto Uzumaki affectionately calls him. He wears a green jumpsuit, orange striped leg warmers, and the standard Konoha flak jacket, which he normally leaves unzipped. His red forehead protector is worn around his waist like a belt. Guy's appearance has not changed substantially during his ninja career, though as a genin his jumpsuit was sleeveless and he wore a scarf around his neck. His appearance even remains almost identical after the Fourth Shinobi World War, two exceptions being Konoha's redesigned flak jacket and the red wheelchair he uses for mobility. During The Last: Naruto the Movie, his right leg is in a cast because of damage he received during the war, but the cast is gone by the time of Boruto: Naruto the Movie.

Abilities
Because of his lack of skill with ninjutsu and genjutsu, Guy did not seem to have a very promising future as a shinobi when he first applied to the Academy. Sakumo Hatake, however, sensed in Guy a willingness to succeed, what he believed was a great strength yet to be fully realized. Sakumo's son, Kakashi Hatake, agrees with this years later during the Fourth Shinobi World War, calling Guy stronger than himself. Over the years, others have echoed the Hatakes' views: Itachi Uchiha warns others not to underestimate Guy; Kisame Hoshigaki, after being defeated by Guy, is impressed that Guy could fight him on two prior occasions without using some of his more powerful jutsu; Madara Uchiha calls Guy the most exciting opponent he's had since fighting Hashirama Senju.

Physical Prowess
Because he's known that he wasn't suited for ninjutsu and genjutsu since he was very young, Guy has been able to dedicate his life to taijutsu; his father, Duy, called this early knowledge of his own strengths and weaknesses a "virtue" most shinobi didn't have. By adulthood, Guy is a taijutsu master, of such skill that Madara Uchiha believes him to be unsurpassed. He is extremely physically strong, able to use his Strong Fist combat style to defeat an opponent with one punch and then send them flying through the wall behind them. He is also extremely physically fast, consistently able to attack an opponent before they're fully aware of his presence, if at all. In Kakashi Hiden, his skills are not hampered by his damaged leg, and in fact its cast makes his kicks more painful to his opponents (and Guy himself).

Guy's unprecedented physical skill is owed to several factors. He trains constantly: tasks he needs to complete anyway he makes into exercises; exercises that aren't challenging him he makes into contests that usually only Rock Lee is willing to join him on; for contests he loses he stipulates new tasks for himself that, by completing, he hopes will help him to not lose again. In all of these cases, Guy's training is quite arduous, either having an almost impossible time limit or a needlessly difficult goal, such as doing 500 laps around Konoha while walking on his hands. The end product, however, is what Tenten calls Guy's inhuman stamina, making physical feats that would be difficult for most others easy for Guy. Competition with Kakashi motivates Guy in many of these regimens and also comes with its own benefits: in his pursuit to beat Kakashi, Guy has devised a way of combating Sharingan-users by focusing on the positioning of their feet to predict their movements and negate the Sharingan's eye-contact-based genjutsu.

Eight Gates
Guy's father taught him when he was a child how to open the Eight Gates, what Duy called the only thing he'd learned during his decades of training that was worth passing to Guy. With each gate he opens, Guy's physical speed, strength, and chakra levels increase; with each gate he opens, his body also takes more and more damage, with the opening of all eight gates causing eventual death. For this reason, Duy stipulated that the Eight Gates were only to be opened in order to protect something or someone precious, a philosophy Guy follows and that he also requires of Lee. Guy has been shown enduring the rigors caused by the gates for periods of time after using them, but inevitably he succumbs to the pain or exhaustion they cause.

Guy has created several different jutsu that he can perform once certain gates have been opened: with the first gate, he can use the pile-driving Front Lotus; with the third gate, he overwhelms opponents with punches through the Reverse Lotus; with the sixth gate, Guy produces a series of rapid punches that ignite his hands through air friction, what he calls Morning Peacock; with the seventh gate, he launches concentrated air pressure at opponents that violently expands on contact, creating what he calls his one-hit kill move, the Daytime Tiger; with the eighth gate, his punches create shock-waves of such power and range that he doesn't even need to make contact with his opponent, what Guy calls Evening Elephant; also with the eighth gate, he has Night Guy, a single kick that is so fast that it distorts the space around him. Night Guy, though it almost kills Madara Uchiha, is responsible for the destruction of Guy's leg.

Ninjutsu
Just because Guy isn't skilled in ninjutsu or genjutsu doesn't mean he can't use them, he simply tends not to; in the anime, he goes out of his way to avoid using ninjutsu, putting on an unconvincing disguise rather than use the Transformation Technique. Among Guy's few ninjutsu-skills are the fire and lightning natures, as well as the ability to summon tortoises like Ningame. Guy is at least knowledgeable about other ninjutsu, recognising the Four Red Yang Formation and speaking informatively about its power and difficulty.

Guy has other practical skills that do not require chakra to use. He is proficient with nunchaku, and with his personal pair, Sōshūga, he can smash through rock and trade blows with Tobi's gunbai. In the anime, he trained Tenten extensively in using her various ninja tools. He at times make herbal remedies to help Lee with his training, but it's not clear if these actually do any good.

Chūnin Exams
After holding them back for a year of training, Guy allows his students on Team Guy (Rock Lee, Neji Hyūga, and Tenten) to enter the Chūnin Exams being held in Konoha. He worries, however, that they may not behave, so he has Ningame keep an eye on them as they prepare to take the exams. Ningame catches Lee trying to use the Front Lotus on Sasuke Uchiha, defying Guy's instructions to only use it while protecting something precious. Guy is summoned to reprimand Lee: he punches Lee as punishment, and then embraces him out of regret from punching him; Sasuke and his fellow Team 7 members are disturbed by the display. Aware that Team 7 are Kakashi Hatake's students, he asks them how Kakashi is. He apologizes to them for Lee's behavior and tells them all to head to the exams' first stage before he departs.

Team Guy advances to the preliminary stage of one-on-one fights held before the finals, and Guy watches his students' matches and cheers them on. When Tenten is badly abused after her defeat by her opponent, Temari, Guy stops Lee from getting into a fight with Temari and her Suna-teammates. When Neji ignores Guy's request to not bring the Hyūga clan's family issues into his fight with Hinata Hyūga, Guy intervenes in the match, restraining Neji so that he won't kill Hinata. When Lee is matched against Gaara, Guy tells him an important observation he's made: the gourd that Gaara has on his back may be significant. Although Lee takes this information with enthusiasm, it doesn't help him against Gaara's Shield of Sand once the fight begins. For this reason, Guy gives Lee permission to remove his ankle weights, thus making him fast enough to bypass Gaara's shield.

The increased speed is insufficient against Gaara, for which reason Guy allows Lee to use the Front Lotus. The stress the Front Lotus does to Lee's body provides a brief opening for Gaara to escape unharmed, which he takes. Lee, meanwhile, still experiences the after-effects of using the Front Lotus and has difficulty fighting off Gaara's attacks. Guy signals to Lee to use the Reverse Lotus. Kakashi expresses disappointment in Guy when he realizes what he's allowing Lee to do, but Guy defends his decision, as becoming a splendid ninja is the most important thing in Lee's life, and defeating Gaara will help him achieve that. The Reverse Lotus ends up failing, as Gaara uses the gourd on his back to absorb the attack. Lee is unable to move afterwards, allowing Gaara to start crushing his arms and legs. Guy intervenes, forcing Gaara to relent.

Although Lee has lost the match and has fallen unconscious, his body gets up through muscle memory so that he can keep fighting. Guy tearfully embraces him, assuring him he's already a splendid ninja. Medic-nin come to check on Lee, but from a cursory examination of his injuries they inform Guy that the damage the Reverse Lotus did to his body is so severe that Lee won't be able to continue life as a ninja. Guy is devastated by the news, blaming himself for not stopping Lee when he had the chance and for teaching him the Reverse Lotus in the first place. A month later, on the day before the Chūnin Exams' finals are to be held, Guy visits Lee in the Konoha Hospital. He finds Gaara in Lee's room, trying to finish him off. Guy threatens to admit Gaara to the hospital as an inpatient if he doesn't leave, which Gaara complies with.

Guy takes Lee to see the final matches the next day. Because of Lee's injuries, most of the first round matches have completed by the time they reach the stadium where the finals are being held; Neji lost in his fight with Naruto Uzumaki. While watching the fight between Sasuke and Gaara, both Guy and Lee are surprised by the speed Sasuke has copied from Lee using his Sharingan, though it makes sense to Guy once he sees Sasuke using Kakashi's Chidori.

Konoha Crush
The Chūnin Exams are interrupted by an invasion of Konoha and most of those watching the finals are rendered unconscious by a genjutsu. Guy is among those who dispel it and he teams up with Kakashi to fend off invading Otogakure forces. While Kakashi arranges a team of genin to go after Sasuke and Gaara, Guy defends the area and then creates an opening for the genin to pass through; Guy worries that they won't be enough, but Kakashi has confidence in them. They return to the fight, eventually eliminating all invaders in the area except for Kabuto Yakushi and Baki, who opt to flee rather than face them. Guy and the others then converge on the site where the Third Hokage fought Orochimaru, but discover that he's died in battle. Guy attends the Third's funeral a few days later.

Search for Tsunade
When Kakashi is about to be captured by Akatsuki member Kisame Hoshigaki on the instructions of his partner, Itachi Uchiha, Guy arrives in time to repel Kisame. Kakashi falls unconscious as soon as he arrives, so Guy carries him over to Asuma Sarutobi and Kurenai Yūhi. They share with Guy Kakashi's earlier warning not to look Itachi in the eye because of his Sharingan, but Guy already knows this and tells them how to combat it: looking at Itachi's feet. He instructs Kurenai to take Kakashi to a medic and Asuma to assist him in keeping Itachi and Kisame busy until the Anbu reinforcements he's requested arrive. Itachi and Kisame withdraw rather than fight.

Guy and the others take Kakashi back to his home to rest, where Guy is informed that Itachi and Kisame are after Naruto. While they're talking, Sasuke comes to visit Kakashi and is confused by his current condition. Guy and the others try keeping the return of Itachi - Sasuke's brother - a secret, but it is unwittingly revealed by Aoba Yamashiro. Sasuke runs off to find Itachi and Guy chases after him. When he catches up, he makes a sneak attack without getting a good look at his target, fearing Itachi's Sharingan. He ends up attacking Jiraiya - who has already driven off Itachi and Kisame - and Guy apologizes once he realizes his mistake. When Guy prepares to head back to Konoha, Jiraiya asks him to take Sasuke, who has been rendered unconscious by Itachi. Guy tells him that Kakashi is in the same condition and muses that this, combined with Lee's injuries, makes him wish for the medical expertise of Tsunade.

Jiraiya reveals that he and Naruto are already searching for Tsunade. Guy asks that they be sure to find her, which Naruto vows to do. Guy is impressed by Naruto's courage and gives him his spare green jumpsuit, telling him it will make a huge difference in his training. Guy departs with Sasuke, assuming that Jiraiya is just as ecstatic by the jumpsuit as Naruto is. (He isn't.)

Sasuke Recovery Mission
When Tsunade is brought back to Konoha to become its new Hokage, Guy tracks her down just after she's finished healing Sasuke and Kakashi and begs her to look at Lee. After examining Lee, she agrees with the other medics' assessment that the damage is too severe for him to continue life as a ninja. She can heal him, but she confesses there's only 50% chance that Lee will survive the procedure; she suggests he not take the risk. Lee is crushed by the news and leaves. When he's gone, Guy shares his regrets for having Tsunade look at him, as now Lee's lost the hope he'd had up until now.

Guy later finds Lee in the same spot where Lee first shared his dream of being a splendid ninja. Lee muses how far he's been able to get in his career using Guy's lessons of hard work and believing in himself, but he now fears that neither of those things can help him in his current situation. Lee asks Guy what he should do. Guy says that Lee has two options: he can give up on the life of a ninja and experience great pain for abandoning his dream, or he can get the operation, and if he dies then he'll at least die pursuing his dream; Guy thinks Lee should do the latter. He reminds Lee of his vow to dedicate his life to making Lee a splendid ninja and, therefore, if Lee's life should end, so will Guy's. Lee is moved by Guy's words and decides to go through with the operation.

Guy is forced to leave Konoha on a mission while Lee has his operation. He completes the mission as quickly as he can and returns to Konoha just as quickly, seeking out Tsunade despite his exhaustion so that he can find out how things went. Tsunade tells him the surgery was a success, which overwhelms Guy with happiness. Moments later they are informed that Lee is missing from his room, which overwhelms Guy with worry. Tsunade realizes that Lee's gone off to help the Sasuke Recovery Team. What's more, he accidentally took her bottle of sake rather than his medicine, which overwhelms Guy with fear that Lee may unleash the Drunken Fist on somebody. Lee later safely returns, and he and Guy immediately resume their training.

Viva Dojo Challenge! Youth is All About Passion!
In the anime, Guy hears about a dōjō that Lee has opened. Guy prepares to challenge Lee in a fight by (poorly) disguising himself as a stranger, but is called away on a mission before he can issue the challenge. When he visits the dōjō afterwards, he runs into Nanafushi, a thief disguising himself as Lee, and quickly knocks him out.

Third Great Beast Arc
In the anime, Guy goes on a mission with Yagura, a ninja of seemingly greater talent than Lee. During the mission, Guy discovers that it is not really Yagura, but actually one of the Three Ryūdōin Brothers who, along with his brothers, seeks vengeance on Guy for their father's death. They trap Guy and Lee in a castle and force them to fight each other through artificial, mute proxies. They discover this trick by communicating through Morse code, then break out by opening the first five gates, the stress of their high-speed attacks causing the constructs to break apart. Guy afterwards explains that he wasn't responsible for their father's death and that their father actually respected Guy, causing the brothers to apologize.

Konoha Plans Recapture Mission
In the anime, Guy leads Konoha's available jōnin to stop a suspected invasion by Takigakure. They later discover that the Taki-nin are just having a training exercise.

In Naruto's Footsteps: The Friends' Paths
In the anime, about two years after Naruto leaves Konoha to train with Jiraiya, another Chūnin Exam is held. Guy proctors the preliminary round between the first and second stage: participating teams must reach the Demon Desert within three days in order to qualify for the second stage. During this period, Team 10 is nearly killed by a giant scorpion while they search for food, so Guy gives them some. Once the preliminary round is over, Guy watches as the second stage formally begins.

Kazekage Rescue Mission
Tsunade sends Team Guy to provide backup to Team 7 on their mission to rescue the Fifth Kazekage from Akatsuki. On their way to Sunagakure to meet Kakashi and the others, they are intercepted by Pakkun, who informs them that Team 7 has tracked the Kazekage to an Akatsuki base in the Land of Rivers. Team Guy is closer to the Land of Rivers than Team 7 is, so they change their course. Along the way they are attacked by Kisame Hoshigaki of Akatsuki, who Guy doesn't know. Kisame covers the surrounding desert with water and fends off Guy's students' attacks with his Samehada sword. Seeing Kisame's abilities, Guy gets the feeling that he's met Kisame before, irritating Kisame that he doesn't remember him.

Team Guy joins forces against Kisame and Guy is able to take Samehada. But Samehada does not allow Guy to wield it and Kisame, meanwhile, is able to trap Lee, Neji, and Tenten in water prisons so that he can fight Guy without interference. Kisame starts to overpower him, forcing Guy to open the first five gates and attack with Morning Peacock. Kisame is defeated, but when Team Guy examines his body afterwards they discover that it is only a doppelganger meant to stall them. They continue on to the Akatsuki base, but when they arrive find they are unable to enter. When Team 7 arrives shortly afterwards, Kakashi identifies it as being a Five-Seal Barrier, maintained by one seal over the entrance and four more somewhere in the surrounding landscape. Neji locates the other four with his Byakugan and Team Guy splits up to remove them.

Although they succeed in bringing down the barrier, thus granting Team 7 entrance, each member of Team Guy is confronted by a duplicate of themselves as soon as the barrier is gone. Guy, like the rest of his team, struggles to defeat himself, and it is only by becoming stronger than he was at the time the duplicate was created that he is able to defeat his; in the anime, Guy defeats his duplicate with Leaf Great Flash. Team Guy reunites with each other after winning their battles and they go after Team 7, arriving in time to cut off Deidara's escape attempt. Unable to get away, Deidara creates a Suicide Bombing Clone, which Kakashi saves them from by using Kamui.

Team Guy watches on as the Kazekage - dead because of Akatsuki - is revived by Chiyo in exchange for her own life. They attend her funeral in Suna a few days later before heading back to Konoha. Kakashi is too tired to walk due to his use of Kamui, necessitating that Guy carry him. Guy does so by giving Kakashi a piggyback ride and challenges their students to keep up with him; although Lee is fascinated by this training regimen, the others are deeply disturbed.

Akatsuki Suppression Mission
In the anime, Guy attends Asuma Sarutobi's funeral.

Three-Tails' Appearance
In the anime, Guy teaches Lee and Tenten how to use collaboration jutsu by tying them together. This turns out to not work.

Pain's Assault
Team Guy returns to Konoha after completing a mission. As they approach the village's outskirts they find a defeated Gamabunta, who informs them of the ongoing invasion of Pain. They rush back to the village and, upon arrival, find Hinata Hyūga badly injured from her fight with Pain. After getting her medical attention, Guy and Lee prepare to help Naruto in his fight against Pain, only to be informed that Naruto has already won. Team Guy joins in the celebration when Naruto returns to the village.

Past Arc: The Locus of Konoha
In the anime, Guy makes a medicine to be given to Tsunade in the hopes that it will bring her out of her coma, which Lee delivers.

Power
In the anime, Guy is part of a force sent to Hachō Village to help the Team 7 in their fight with Kabuto Yakushi. When they arrive, Guy and Lee fight the Nine-Tailed Naruto Clone, but find they must open the fifth gate in order to keep up with its speed and strength. After Kabuto retreats, the Konoha-nin investigate The Hole to try and discover what Kabuto was so interested in.

Paradise Life on a Boat
While Konoha prepares for the approaching Fourth Shinobi World War, Guy is part of a team assigned to guard Naruto as he is sent into seclusion, a fact Naruto is not to be informed of. In the anime, as they make their way to their destination in the Land of Lightning, they take an indirect route so that Akatsuki cannot find Naruto. Before they can even leave the harbor in the Land of Fire, they are attacked by a Giant Marlin. They try to help a fisherman, Yūsuke, catch the marlin, but Naruto discovers that the marlin is compelled to attack because of a shuriken embedded in its head. When the shuriken is removed, the marlin leaves them alone and they're able to set sail.

Guy and the other bodyguards become seasick soon after starting their voyage, requiring that they briefly stop at Benisu Island until they recover. They next encounter a ghost ship, whose crew was killed by the Giant Corpse Crab. Guy and the others help the crew avenge their deaths by defeating the crab, thus releasing their souls. As they continue their trip, Guy is kidnapped by a giant bird that wants Guy to babysit its chicks. When Naruto and the others come to rescue him, the bird takes them to a volcano where the "ultimate summoning beast" lives. Guy and the others team up with the bird and other local animals to defeat the beast.

Continuing on, their food reserves start to run low and Guy and Naruto, in their desperation, eat a mushroom purchased from bandits. The mushroom makes them act violently, but they regain their senses with the help of Shima's cooking in time to stop the bandits from stealing their cargo. Towards the end of their trip, Kakashi comes looking for Guy. Guy gets it into his head that it is not actually Kakashi but rather an impostor and attacks him. When the others aboard start defending Kakashi, Guy concludes that they are also impostors and attacks them as well. Kakashi is able to convince Guy that he's the real Kakashi by recounting something from when they were younger. Kakashi then explains that he's answering a distress signal that Guy sent. Guy has no memory of doing that and suspects he sent it accidentally, so Kakashi returns to Konoha.

Fourth Shinobi World War: Countdown
Guy is battling seasickness by the time they reach the Island Turtle and Aoba Yamashiro looks after him until he recovers. Once he's better, he goes to the Falls of Truth, where Naruto previously faced and overcame his inner-self. Aoba dares Guy to do the same, suspecting that Guy's inner-self isn't human. As his inner-self emerges from the falls, it ridicules Guy for his old age and his loss of the youth he constantly preaches about. Guy demands that his inner-self reveal itself, but what emerges from the falls appears to be an insect. Assuming this is his inner-self and that it's been deformed by his loss of youthful spirit, he attacks it to mold it back into shape. Aoba informs Guy that it's not actually his inner-self, enabling him to recognize it for what it truly is: a puffer fish.

Killer B emerges from the falls and informs them that it is not puffer fish, but rather Kisame Hoshigaki of Akatsuki, who is trying to escape with information about B and Naruto. After quickly incapacitating B and Aoba, Kisame attacks Guy and starts swimming to the ocean to send out the intel he's gathered. They're unable to move as quickly as Kisame can swim, so B flings Guy across the island in order to head Kisame off; this isn't enough, so Guy summons Ningame in mid-flight for him to use as a jumping off point to launch him the rest of the way. When he catches up, Kisame has already passed the intel to a shark, the identity of which he hides with one thousand more so that the shark can escape the island. Guy tries to destroy the sharks with Morning Peacock, but there are too many and he's forced to open the seventh gate. Kisame tries to stop Guy with his Great Shark Bullet Technique, which Guy counters with Daytime Tiger.

The Daytime Tiger is unimpeded by the Great Shark Bullet and directly connects with Kisame, creating a giant aftershock that not only defeats him but also destroys the remaining sharks. As Guy collects the intel, Kisame states his surprise that Guy could withhold a jutsu as powerful as the Daytime Tiger until their third encounter. Since Guy doesn't remember their previous two encounters, Kisame attempts to keep fighting, prompting Guy to knock him out. He takes Kisame back to the others so that Aoba can interrogate him. Rather than be used to betray his allies, Kisame breaks free of his confinements through sheer will, traps himself in a water prison so that Guy and the others can't stop him, and summons sharks to eat him alive. Guy deeply respects how and why Kisame chose to die, so vows to remember him for the rest of his life.

They afterwards examine the intel that Kisame was trying to send, which turns out to be booby-trapped: they are each caught in a water prison and are trapped alongside a shark. Guy finally succumbs to the rigors of his earlier use of the Eight Gates and can't fight off his shark, requiring that the others rescue him. Another shark, meanwhile, is able to escape with Kisame's intel.

Fourth Shinobi World War: Confrontation
When the Fourth Shinobi World War finally starts, Guy is reassigned to the Third Division of the Allied Shinobi Forces; his body is still suffering from using the Eight Gates, which Sakura Haruno tries to heal. Guy recovers by the time that the Third Division is called to help the Surprise Attack Division, assisting Kakashi, Sakura, and Lee with holding off the reincarnated Gari, Pakura, Haku, and Zabuza Momochi. Zabuza covers the area in mist to hide his and the others' movements, placing the Third Division on the defensive. When casualties start mounting, Guy does his best to protect the other Allies, but reminds those nearby that deaths are inevitable and that they can't let that destroy their resolve.

Although Kakashi is able to defeat Zabuza and dispel the mist, fighting continues into the next day due to the opposing reinforcements: the reincarnated Seven Ninja Swordsmen of the Mist. In the anime, Guy teams up with Kakashi to keep Jinpachi Munashi and Kushimaru Kuriarare busy until the Sealing Team can deal with them. They're eventually able to reduce the number of reincarnated ninja to three, at which point part of the White Zetsu Army arrives to fight the Third Division. One of Naruto's shadow clones arrives shortly afterwards, helping defeat the Zetsus. In the anime, the Third Division is attacked by one additional reincarnated ninja, Chen. A taijutsu expert like Guy, Chen is able to gain the advantage because his immortal body doesn't tire out, unlike Guy's. Lee saves Guy and, by talking with Chen and fighting him, is able to return his soul to the Pure Land.

Fourth Shinobi World War: Climax
Guy and Kakashi eventually leave the Third Division to join the original Naruto and Killer B in their fight with Tobi, arriving in time to stop Tobi from capturing Naruto. Guy frees Naruto from the coral that's restraining him and they all attack the reincarnated jinchūriki that Tobi is using as his Six Paths of Pain. Tobi has two of the jinchūriki enter Tailed Beast Mode, following which the Four-Tails attempts to swallow Naruto. Guy and Kakashi want to help him, but must deal with the others first: while Kakashi deals with the jinchūriki, Guy repels the Six-Tails' Wisdom Wolf Decay using Morning Peacock. Naruto, meanwhile, is able to escape the Four-Tails and release it from Tobi's control.

Tobi forces the remaining jinchūriki to also enter Tailed Beast Modes, expecting to destroy Guy and the others before they can release another of the tailed beasts. As five Tailed Beast Balls bear down on them, Guy considers opening all Eight Gates. It ends up not being necessary as Naruto, by entering his own Tailed Beast Mode, deflects their attacks and subsequently frees them from Tobi. Tobi is forced to recall the tailed beasts into the Demonic Statue of the Outer Path, which he uses against Naruto, B, Kakashi, and Guy. Fighting continues into the night, with neither side emerging victorious. When a light descends on the reincarnated jinchūriki, a sign that the Impure World Reincarnation has been canceled, Tobi takes drastic action and prematurely initiates the Ten-Tails' revival. When they realize what Tobi is doing, Guy and the others focus on destroying the Demonic Statue before it can complete its metamorphosis into the Ten-Tails.

Tobi defends the Demonic Statue from all of their attacks and, as ever, is himself seemingly impervious to damage, with everything passing through him. After the exchange, Kakashi notices some slight damage to Tobi's mask, which he has a theory about. To test this, he has Guy and Naruto attack Tobi: Guy allows Tobi to absorb the Sōshūga he's been using, creating an opening for Naruto to attack with Rasengan. Tobi fazes through this, but Kakashi uses his Kamui on the Rasengan, causing Tobi to take damage. This confirms Kakashi's theory that Tobi is also using Kamui and must therefore have the companion Sharingan to Kakashi's. Tobi confirms this, troubling both Kakashi and Guy because of what this may mean. Nevertheless, this information gives them a way of attacking Tobi, though Kakashi is so distracted in thought that he doesn't join in until Guy brings him back to his senses. Their combined efforts succeed in destroying Tobi's mask. When they see his face, Guy and Kakashi recognize Tobi as Obito Uchiha.

Guy and, in particular, Kakashi are surprised that Tobi is Obito. Naruto doesn't know who Obito is so, so Guy explains their history with him. Naruto notes that the past doesn't change the fact that Obito is now their enemy, which Guy agrees with and uses this to try to help Kakashi recover from the shock of seeing Obito. Obito is soon joined by a reincarnated Madara Uchiha, who decides to take Naruto's Nine-Tails and Killer B's Eight-Tails before the Ten-Tails is revived. Guy helps defend them - entrusting Obito to Kakashi - but Madara is too formidable and Guy soon becomes tired. Madara tells them that fighting against him is futile, which Naruto refuses to believe. Guy is moved by Naruto's confidence and attacks Madara with Daytime Tiger, propelling him away and leaving Guy no longer able to move. Naruto and the others team up to try and destroy the Demonic Statue, but they fail and the Ten-Tails is revived.

B carries Guy to Naruto, who takes him into his Tailed Beast Mode to keep him safe while his chakra replenishes. Battle with the Ten-Tails interrupts the process before Guy is fully restored, requiring that Kakashi support him. The Ten-Tails attacks again, but they are saved by the arrival of the rest of the Allied Shinobi Forces; Shizune heals Guy's injuries. When the Alliance restrains the Ten-Tails, Guy and Lee open the fifth gate in order to join the attack against it, but the Ten-Tails breaks free at the last moment and repels them. When Neji is killed in the following battle, Lee mourns for him; Guy comforts him by telling him that Neji will live on so long as they continue to fight for the cause that he gave his life for. Naruto gives them version 1-like cloaks to protect them and strengthen their attacks, which they and the rest of the Alliance use to remove the Ten-Tails from Obito and Madara's control.

Birth of the Ten-Tails' Jinchūriki
Guy does what he can to contribute to the battle, but the prolonged fighting has left him exhausted and eventually Lee must help him walk. Following Obito's defeat, they start slowly heading towards where the rest of the Alliance has engaged in another battle. Along the way they notice the Fifth Kazekage taking Naruto and Sakura Haruno in the opposite direction, towards where Obito was left in Kakashi's custody. Sensing something is wrong, Guy instructs Lee to head back, against Tenten's objections. They get back in time for Guy to save Kakashi from a Truth-Seeking Ball fired by somebody Guy doesn't recognize: Madara Uchiha. Guy is surprised to learn that it's Madara's, whose appearance has changed now that he is the jinchūriki of the Ten-Tails.

Kakashi and the others explain that Madara is now impervious to all attacks except for senjutsu and taijutsu. Although the reincarnated Fourth Hokage is technically able to use senjutsu, he can't do so in his current state. Guy therefore decides it's his responsibility to fight Madara and opens the seventh gate. He attacks with Daytime Tiger, but Madara survives and Guy, weakened afterwards, must be saved from one of Madara's Truth-Seeking Balls by Lee. With Guy's attack having failed, Kakashi decides that they stand no hope against Madara. Guy corrects him: he still has the Eight Gates Released Formation. Kakashi and the Fourth try to convince him not to, but Lee tearfully understands Guy's reasons. As he punctures his heart to open the eighth gate, Guy thinks about his father and reflects that his comrades are precious enough to him to give his life protecting them.

Guy attacks Madara with Evening Elephant, but the pain he experiences forces him to stop after only the first step. When Madara returns, eager to see what Guy can do, Guy starts over, sequentially delivering the first four steps of the Evening Elephant to Madara. Kakashi and the others, aware that Guy has a time limit, team up to eliminate some of the Truth-Seeking Balls that Madara is using to defend himself with. This allows Guy to hit Madara with the Evening Elephant's fifth step directly. Madara survives and, though he's winded, he invites Guy to attack him again. Guy tries additional Evening Elephants that do gradually damage Madara but, with his life about to expire, Guy realizes he will need to use Night Guy if he hopes to end things. He charges at Madara and kicks him in the side, obliterating part of Madara's torso and shattering the bones in Guy's right leg.

Guy succumbs to the use of all Eight Gates and passes out; his body starts roasting from the inside and his damaged leg begins to crumble into ashes. Madara's body regenerates from the damage it received and he, as thanks to Guy for being such a great opponent, fires a Truth-Seeking Ball at Guy to put him out of his misery. Naruto repels the Truth-Seeking Ball and uses his new Yin–Yang Release to stabilise Guy's life-force. After attacking Madara, Naruto takes Guy to Lee and entrusts him to his care, assuring him that Guy will live.

Kaguya Ōtsutsuki Strikes
Despite Naruto's attempt to stop him, Madara is able to cast Infinite Tsukuyomi, trapping the still-unconscious Guy and the rest of the world in a dream. Naruto and Sasuke Uchiha are eventually able to release the Infinite Tsukuyomi, thus freeing the world and ending the war.

Blank Period
Because of the damage done to his leg in his final attack against Madara, Guy is confined to a wheelchair for the rest of his life.

Kakashi Hiden: Lightning in the Icy Sky
A year after the end of the war, Konoha is hired to provide security for the maiden voyage of the Tobishachimaru. Guy, having always wanted to fly, has Lee sneak him aboard, threatening to stop being his teacher if Lee refuses. When Kakashi catches him, Guy claims to have no interest in flying and that he merely wants to demonstrate that he can continue to be a ninja despite his leg injury. Kakashi doesn't believe him, but lets him stay and finds a place for them to ride out the trip as stowaways. During the voyage, the Tobishachimaru is hijacked by the Ryūha Armament Alliance, who demand that Konoha release their leader from the Blood Prison; they will start killing hostages if Konoha takes too long and will blow up the Tobishachimaru if their demands aren't met.

While Kakashi confronts the hijackers to try and rescue the hostages, Guy assists Kakashi's ninken with locating the explosive tags spread around the Tobishachimaru. Once all the explosive tags are dealt with, Guy also confronts the hijackers, drawing Rahyō into battle. Even though his leg is in a cast, Guy remains as fast as ever, allowing him to evade Rahyō's ice-augmented physical attacks. He is even able to deliver some successful kicks, though has difficulty disguising the pain it causes him. He brings out his Sōshūga in order to engage Rahyō, but watching Sōshūga's rapid swinging triggers his motion-sickness. Rather than be debilitated by it, Guy turns it into a fighting style he calls Seasickness Fist. While Rahyō struggles to hit Guy, Kakashi is meanwhile able to free himself from his restraints and fights Kahyō. Kahyō creates a large hole in the Tobishachimaru that starts sucking out the hostages. Kakashi catches Guy before he's sucked out too, but cannot maintain his hold on the ship's hull. Despite Guy's plea for Kakashi to save himself, he loses his grip and they start falling.

As they fall through the air towards the ground far below, Guy makes eye contact with Kakashi and together they accept the fact that they're about to die. They and the hostages are saved by Sai, who takes Guy and the hostages to safety while Kakashi returns back to the Tobishachimaru. Guy returns to Konoha and is summoned before Tsunade. He tries to come up with a plausible reason for why he was aboard the Tobishachimaru, but she doesn't believe him. She's forced to take a call from the Third Tsuchikage before she can punish him, so she tells Guy to sketch the faces of the hijackers. A few months later, after Kakashi has become the Sixth Hokage, Guy is training with Lee when he sees Kakashi reading a letter from Kahyō. Guy pretends disgust by their relationship, but states he won't let it interfere with his duties as Kakashi's adviser.

The Last: Naruto the Movie
When the Moon starts threatening to crash into the Earth, Guy stays by Kakashi's side as he organizes Konoha's defense.

Konoha Hiden: The Perfect Day for a Wedding
Guy is invited to Naruto's marriage to Hinata Hyūga. He gets up early one morning to do laps around Konoha until he can think of what present to get them. He invites Lee to join him, but Lee has just done the exact same thing and failed to come up with anything to get for Naruto. Guy suggests that Lee try coming up with a gift for Hinata instead, while he thinks of a gift for Naruto. Lee thinks about Hinata's post-wedding life of childcare and housework. Guy thinks of Naruto's post-wedding life of home maintenance and carrying groceries. Both simultaneously conclude they should buy dumbbells to prepare Naruto and Hinata for their lives ahead. Completely satisfied with this reasoning, Lee and Guy embrace in a long, tearful hug.

On the day of the ceremony, Tenten instructs Lee and Guy about how they should behave at weddings.

Epilogue
On the day of a Five Kage Summit taking place in Konoha, Kakashi - now retired - visits Guy and they reminisce about the past.

Boruto: Naruto the Movie
Guy watches the final round matches of the Chūnin Exams taking place in Konoha alongside Kakashi and Iruka Umino.

Naruto Shippūden the Movie
Guy is part of one of Konoha's attack forces sent against Mōryō's army of stone warriors, a stall tactic while Naruto and his team help Shion reseal Mōryō.

Naruto Shippūden the Movie: The Lost Tower
Twenty years in the past, Guy, Kakashi, and their peers wait in line for the grand opening of Ramen Ichiraku.

Road to Ninja: Naruto the Movie
When Naruto is sent to the Genjutsu World, he meets that world's Guy: he is a depressive, unenergetic, middle-aged shinobi who thinks of himself as an old man past his prime.

Trivia

 * In the Shonen Jump magazine, Viz rendered Guy's name as "Mighty Guy" in some of the earlier chapters; this was changed back to "Maito Gai" in most of the graphic novel stories, and later changed to "Might Guy" when the guidebooks were released.
 * The name "Might Guy" is a joke aimed at the "hot-headed hero" archetype that appears in many movies and anime.
 * Guy's appearance and mannerisms seem to be based off those of Bruce Lee. He even wields nunchaku and wears a jumpsuit.
 * Studio Pierrot's Settei sheets of Guy show that he was 141 cm in Naruto Shippūden the Movie: The Lost Tower, 151 cm during the Third Shinobi World War, and 170 cm during the Nine-Tails' attack on Konoha.
 * According to the databook(s):
 * Guy's hobbies are repeated side-steps, and hitting focus mitts.
 * Guy wishes for a rematch with Kakashi.
 * Guy's favourite foods are super-spicy curry rice and curry udon, though he finds it impossible to dislike food.
 * Guy's favourite phrase is.
 * Guy has completed 788 official missions in total: 86 D-rank, 270 C-rank, 210 B-rank, 199 A-rank, 23 S-rank.
 * In Ultimate Ninja Heroes, Guy calls himself the "Beautiful Savage of the Leaf Village".
 * In Naruto: Shippūden episode 359, Guy states that he is an agnostic of the Uchiha's patron deity, which is located in the Naka Shrine.

Quotes

 * (To Lee) "Yes!! This is what youth is all about!"
 * (To Lee) "For those who don't believe in themselves… hard work is worthless!! …You are very much like me, Lee. I used to be a loser too. But these days I can even win against the elite genius Kakashi. "I want to prove that even without ninjutsu and genjutsu I can become a great ninja" that's your nindō right? That's a great goal, it's worth working hard for!"
 * (To Kakashi) "What would you know about that boy? That kid has a precious thing he would give up his life to prove. So I wanted to turn him into a man that could accomplish it… That is all…"
 * (To Lee) "You worked hard Lee, there's no doubt in my mind the surgery will be a success. You have the power to shape your own destiny. And on the one-in-one thousand, no, one in a million chance something to happen to go wrong, I will die right along with you. Since the day I met you, my nindō has been to train you to become the most splendid ninja possible. That's a promise!"
 * (About Kisame Hoshigaki) "Water Release ninjutsu… and that huge sword! You must be… …Someone I've met before!"
 * (About Kisame) "He was a worthy opponent! A man who lived and died like a real shinobi! Kisame Hoshigaki! I'll remember that name for the rest of my life!"
 * (To Kakashi) "The springtime of youth has yet to fade away! Don't lose hope! We may not always be able to accomplish all the things we wish for… but if we only do the things we want to do, we'll never start… just like my challenges to you. This is by no means just a show of bravery or courage. The green days of Konoha are over. The time has come to become the red beast."
 * (To Madara) "…That may be true… but they don't just rot and die!! They will become nourishment for the new, fresh leaves! The time when a new spring comes and the fresh leaves bud… is the peak of youth!! It's the time to burn, deep crimson!!!"