The manga series Baki the Grappler and its sequels feature a large cast of characters created by Keisuke Itagaki. It follows teenager Baki Hanma as he trains and tests his fighting skills against a variety of different opponents in deadly, no rules hand-to-hand combat. His goal is to eventually defeat his ruthless father Yujiro Hanma, who is touted as "the strongest being on earth" and whom he despises. Many of the characters are fighters trained in various forms of martial arts with skills that reach superhuman levels.

Main characters Baki Hanma

has been training in martial arts since the age of three, and has trained under various teachers and coaches throughout his life. At the age of thirteen, he decided to take his training into his own hands and left the coaches to perform more intense training in the footsteps of his father, Yujiro Hanma. He later meets with his father and becomes disillusioned as to his father's true character, and afterwards, aims to defeat and kill him. Baki first fought in the no-rules arena run by Mitsunari Tokugawa at fifteen, and went on to become its champion without losing once. Including techniques from many different martial arts, he does not adhere to any specific style. Fighting once a month, Baki thoroughly studies his opponent leading up to their match. He eventually develops the ogre/demon face on his back when fighting his brother, Jack Hammer, but manages to suppress it. Unlike Yujiro, Baki chooses to control his killing intent and fight his battles fair and honorably no matter what the outcome. Baki has encounters with all the escaped convicts in the second manga series. He is then faced with a new foe from the prehistoric era, Pickle the caveman, after Kaio Retsu and Katsumi Orochi are defeated by him. The outcome of the match between Baki and Pickle could be considered to have gone either way: Pickle was the one who was left standing after the fight with Baki, but inadvertently used a "weapon", in the form of a martial arts technique, to beat him. As stated by the onlookers a "weapon" is a tool used by the "weak" against the "strong", which would make Baki the true winner of the fight for having cornered Pickle. Subsequently, Baki's wish to have dinner with his father like a normal family is granted. Yujiro Hanma goes to his house and eats the dinner prepared by his son, dispensing never before seen knowledge with class and proper mannerisms. As thanks for preparing the meal, Yujiro invites Baki to a dinner "in his own style" at Tokyo's best restaurant. At one point during the dinner Baki asks Yujiro why he had to kill his mother; Yujiro refuses to explain his motives "to a resentful brat" and Baki grows confrontational. This triggers their final conflict, and the final part of the manga. The gruesome fight that ensues leaves Baki a broken mess despite using remarkable techniques that earn him the praise of his father. However, Yujiro recognizes Baki's unique fighting spirit and acknowledges that he can no longer be so selfish as to call himself the strongest being on Earth. To thank Baki he starts using imaginary cooking to prepare Miso soup. Baki plays along but says the soup is a little salty, which angers Yujiro, but when he "tastes" it himself he discovers that the miso was, in fact, salty. Baki claims the moral victory due to being able to get his father involved in his own fantasy. The conflict ends in a tie, both fighters recognizing each other's greatness. In the fourth manga, he is still seen participating in arena fights and engaging in regular intensive training, but has become bored with his day-to-day life.

Yujiro Hanma

, nicknamed and often called , is the father of Baki Hanma and Jack Hammer. A genius fighter, he is known to have mastered all styles of unarmed combat. His repertoire apparently includes all of the well-known fighting styles like karate, taekwondo, boxing, judo, ju-jitsu and wrestling, as well as some more esoteric ones such as the secret udondi style, passed onto only the eldest sons of the Ryukyu Kingdom royal family. He has been fighting on the battlefields, using only his bare hands, since the age of sixteen, when he fought against both American and Vietcong forces in the Vietnam War. Since then, it appears that he has obtained respect from the American forces even going so far as having them recognize him as his own national power, with each U.S. president swearing friendship to him. He is sadistic and referred to as a monster, even by Baki, who claims he can not go a day without hurting someone. When Yujiro flexes his back muscles, it appears to take the shape of a demon or ogre's face, increasing his strength and combat abilities. It is said that when he started fighting for pleasure rather than survival, the image of the demon's face appeared on his back. His many physical displays of sheer strength include: stopping an earthquake with a punch to the ground, being struck by lightning with no effect on health, ripping a wooden table into two and then those two pieces together into quarters, cutting a glass table in half only using his finger as if it were a diamond, drinking a whole bottle of high grade Brandy in one gulp with no intoxication. Since his fight with Baki went viral, Yujiro is annoyed to find that he has gained unwanted fans and public attention, and has referenced several young children asking for his autograph since the fight.

Doppo Orochi

, known by numerous nicknames such as the , and , is a 10th dan karate grand master and head of the style of karate. Practicing martial arts for 50 years, he is one of the few people in the world able to stand toe-to-toe with Yujiro. Doppo has two scars on his face from when Yujiro jumped him ten years earlier. In their proper fight that takes place in the underground arena, Yujiro gouges Doppo's right eye out and kills him by stopping his heart. However, Doppo is revived by Kureha Shinogi. In the underground tournament, Doppo fights Richard Filth in round one and Yu Amanai in round two before facing another master, Goki Shibukawa, in round three, which he loses after a brutal match. After that loss, he decides to close down his dojo and start his training all over again. He eventually fights the escaped American convict Dorian in the second manga series. Dorian manages to cut off Doppo's hand with a strange wire-cutting technique in which he uses a wire blade projected from a lighter. Doppo later avenges this loss when he, Katsumi, and Retsu track Dorian down. Shortly after this however, Dorian escapes from the hospital and uses an explosive that is implanted into his hand to blow off part of Doppo's face. Doppo later returns to have a battle with Mohammad Alai Jr. Doppo is the star of the spinoff manga Baki Gaiden: Kenjin.

Kiyosumi Kato (Japanese); Robbie Daymond (English) is a top student of Doppo Orochi who believes karate should be no-holds barred and fights attacking areas such as the eyes. Three years ago, he left Doppo's dojo and worked for the yakuza, honing his skills in fights against guns and knives. After both watching Baki, Doppo shows Kato the underground arena. Kato's attitude is best described as arrogant, but usually being the butt of a joke; especially around Doppo, Katsumi, Tokugawa, and Baki. However, it is shown that he truly admires and cares for Doppo. Kato's first opponent in the tournament is injured by Yasha Ape Jr. before the match, so he tries to fight the ape, but is also beaten and drops out due to injury. Kato shows up in the second manga series and fights against the convict Dorian in his secret underground hiding place. Kato has his face scarred horribly from a broken glass bottle and is announced "dead" upon his body being found by Retsu in the Shinshinkai building. It is later revealed that Kato is alive.

Atsushi Suedo (Japanese); Liam O'Brien (English; Netflix Dub), Michael Wronski (English; Sentai Filmworks Dub) is a 3rd dan Shinshinkai karate student, who is defeated by Baki in a karate tournament. When Kato vandalized the Shinshinkai building, Suedo was one of many who tried to defeat him. Like the rest of his friends, he failed miserably. He later has a fight with Dorian in the convicts saga, to avenge Kato's defeat, but he fails and is nearly killed by falling from a rollercoaster. He reappears in the third manga, alive and well.

Mitsunari Tokugawa (Japanese); Matthew Yang King (English) is an old man of very small stature who runs the underground arena beneath the Tokyo Dome, where fighters of any style compete in hand-to-hand combat with no rules. While not a fighter himself, he is very knowledgeable not only about martial arts, but about the fighters as well, such as their birthdays and family members. Tokugawa has the final say in each and every one of the battles that take place in his arena. While he usually prefers to keep every fight in order, he will sometimes bend the rules if it means amplifying the fight in some way, even going so far as to threaten one of his own doctors with a knife when they tried to stop a fight. In order to find the strongest alive, he decides to hold the underground tournament in arena. Tokugawa is close personal friends with Doppo and Antonio Igari, as well as acquaintances (though not exactly friendly) with Yujiro. He is one of the few people to ever outsmart Yujiro. When Yujiro attempted to upset the balance of his tournament, he had his snipers, who he had secretly stationed around the arena, to shoot him with enough tranquilizer to put down a blue whale. This gives him the very rare achievement of being the only person who has ever knocked Yujiro unconscious.

Izo Motobe

is an old Japanese jujutsu master, who starts training Baki for his fight against his former student Junichi Hanada, but it turns into a fight against Mount Toba. Having lost to Yujiro eight years ago, Motobe develops new techniques in order to fight Yujiro, but usually fails. Motobe participates in the tournament where he is beaten in the fourth match by sumo wrestler Kinryuzan. He continues to offer commentary for future fights and insight into various and often obscure techniques an example would be Baki's life like shadowboxing technique. He later appears again in the second manga, this time fighting against the convict Ryuuko Yanagi. After seeing Baki and Yujiro fight he takes his training even further, even claiming that he will "protect" Yujiro from Musashi.

Kosho Shinogi

is a karate expert who fights using a style where the attacks are not blunt blows, but slashes that cut the opponent. His special technique allows him to cut his opponents' nerves, blood vessels, and lymph ducts, earning him the nickname . In his fight with Baki, Kosho disables Baki's right arm and blinds his right eye, but is knocked out. In the first round of the tournament, he fights his older brother Kureha, who gives up after seeing Kosho's resilience. In round two, he fights Goki Shibukawa and though he breaks Goki's fake eye he still loses. Kosho returns in the second manga series, and fights against the convict Doyle. Doyle uses an explosive device in his chest to defeat Kosho, and it is later shown that Kureha has been taking care of his burn wounds following the battle. He is shown putting himself through harsh training after seeing Baki and Yujiro fight.

Kureha Shinogi