The series' protagonist, Takehiko Inoue's take on the legendary sword saint, Musashi Miyamoto.
- Adaptational Badass: Musashi had never single-handedly defeated the entire Yoshioka school, before Vagabond.
- The Anti-Nihilist: Musashi's faced time and again with the meaninglessness of his desire to become invincible, along with the fact that his search for strength has cost him the lives of hundreds of people for no reason whatsoever and separated him from the one woman he truly held any affection for. But Musashi never backs down; even when confronted with how small he is in the grand scheme of the endless universe, and no matter how many times his ideals get insulted or proven false, he always picks himself back up and does his best to learn from his past mistakes.
- Be Careful What You Wish For: Musashi's constant pursuit to better his skills pays off when he manages to single-handedly overcome a seventy-man army out for his blood, and as such becomes a national figure so widely known that samurai from far and wide begin holding his name in deep reverence. You'd think Musashi, given his goal of being "invincible under the sun," would be pleased about it—but in the aftermath of the Yoshioka school massacre, he begins to see just how meaningless the title of invincibility truly is, beginning to understand the value of life and non-violence.
- Big Brother Mentor: to Jōtarō in the earlier parts of the story, to Iori in the latest ones.
- Blood Knight: At first; during his younger years as Takezō Shinmen, he willingly risked his life in meaningless battles solely for the instant gratification he gets from bloodshed. As time goes on and he gradually grows more enlightened, he actually expresses discontentment towards his life of violence and actively seeks to solve problems without needlessly hurting others.
- Break the Haughty: Musashi's greatest flaws are his overconfidence in his skills and his constant desire to prove himself. It is only when he suffers his first real defeat at the hands of Inshun that he recognizes the value of respecting his opponents and how narrow-minded his own view of his swordsmanship truly was.
- Byronic Hero: Introspective? Yes. Intelligent? In the heat of battle, he proves to be quite the Genius Bruiser. Arrogant? His extreme desire to prove himself tends to overshadow his more sensible side. Extremely passionate about his dreams? Understatement of the century. Intensely dedicated to his own philosophy, without any concern for any established standards set by society? Yup. The only things he distinctly averts from the Byronic archetype is being cynical and sexually active; on one hand Musashi's one of the most optimistic characters in the whole series, and in the other he constantly rejects women's advance on him because he just wants to focus on the way of the sword.
- Can't Hold His Liquor
- Character Development: Musashi starts out the series as a violent youth looking for glory and to prove himself as the strongest warrior in the land. As his martial prowess grows, he also learns a lot from all the people he meets (both warriors and otherwise) and gradually realizes the value of life and the importance of solving problems without violence.
- Chaste Hero: a great contrast to Matahachi. Musashi constantly rejects women's advances and a couple of marriage proposals. He wants to stay focused and live by the sword.
- Combat Pragmatist: In keeping with both his characterization from the novel (as well as historically) Musashi occasionally eschews fighting purely honorably in favor of using what simply works. For example, he begins his fight against the seventy Yoshioka swordsmen by incapacitating/killing them with unarmed blows before attacking with weapons he has taken from his opponents, and attacking from the shallowest direction (that is, that with the fewest swordsmen between him and his target)... and he doesn't hesitate to resort to the Groin Attack either!
- Desperately Seeking A Purpose In Life: The whole manga centers around him discovering what it truly means to become "invincible under the sun," as he spent most of his youth just purposelessly killing others like a savage. At first, he comes to the conclusion that he must slay everyone at the top in order to bolster his own standing, but later on understands that his relentless killing of numerous samurai has trapped him in an endless spiral of death.
- Dramatically Missing the Point: Takuan forces Takezō to reevaluate his entire life right at the beginning of the story, forcing Takezō to realize how he was wasting himself in headlong, youthful recklessness. Takezō decided to actually make something of his life by going out and facing truly strong, renowned samurai all across Japan, seeking to become "invincible under the sun" in an Authority Equals Asskicking kind of mindset. When he finds that becoming invincible doesn't satisfy him at all, Musashi comes to seek personal and spiritual enlightenment by understanding the value of peace and harmony, learning the necessity of acting without violence.
- Dude, Where's My Respect?: Musashi doesn't necessarily care about earning the respect or love of others, but his main goal is to make his name known as the one "invincible under the sun."
- Fastest Gun in the West: A samurai version of this trope. As his reputation grows, ronin hoping to make a name for themselves seek him out and try to kill him. Needless to say, they all fail.
- To Matahachi. Matahachi is a hedonistic man who largely pursues temporary pleasures to fill the hollow void he's left in himself, constantly indulging in self-pity and fuming over the success of others, outright willing to steal other samurai's names in order to better his own lot in life—it's telling that it takes the death of his mother, as well as whole years of lying to her and nearly everyone around him to get him to start manning up. Musashi, on the other hand, relentlessly tries to better himself as a warrior without much concern for how others view him, willing to learn from every single misstep he makes while out on his quest and freely putting himself in less-than-ideal situations all to gain a better understanding of his swordsmanship and his place in the world.
- To Kojirō Sasaki. Kojirō's a happy-go-lucky Manchild who can easily win the love of an entire village within a day; Musashi's mature, aloof, gruff, and doesn't tend to socialize at all (unless they happen to be particularly skilled swordsmen). Kojirō constantly goes after women without rest, while Musashi's fixated singularly on Otsū. Kojirō grew up loved by his father-figure and was treasured in his community, while Musashi grew up constantly being manhandled by his abusive father and ostracized by those who saw him as a "demon child." But both Kojirō and Musashi love using their swords in battle, are always restlessly searching for opponents to spar with all in the name of bettering their own skills, and are so deeply connected to the sword that the two of them can hold a conversation practically just by swinging sticks at each other in place of blades. Their passion for the sword is the one thing the two have in common.
- To Tōji Gion. At the start of the story they are both violent and bellicose swordsmen that only want to fight tough opponents. However, after Musashi loses against Inshun in their first fight, he starts looking for deeper things in life than just being the strongest in the world. On the contrary, Tōji after that very fight gets demoralized, thinking that it is impossible to achieve Inshun's level, and he becomes crazy and loses his path, eventually getting killed by Musashi during the Yoshioka arc. Tōji Gion is an example of what would have happened to Musashi if he didn't change his visions about life.
- To Baiken Shishido. Similarly to Tōji, Baiken is an example of what would have happened to Musashi if he didn't follow the light and instead chose to follow the downwards spiral of death.
- To Ittōsai Itō. Similarly to Tōji and Baiken, Ittōsai is an example of what could happen to Musashi in the future if he becomes an accomplished swordsman but remains extremely violent and without seeking spiritual growth.
- To Hyōgonosuke Yagyū. Both are stated to be very similar in terms of ability and understanding of the sword. The difference is that Hyōgonosuke likes to indulge in sex pleasures, while Musashi is strictly a Chaste Hero.
- To Jōtarō and Iori. Their enthusiasm on following the path of the sword and being his apprentices is a reminder of when he was a kid like them and wanted to live by the sword, but still was innocent and not tainted by the evilness of the world.
- To Sekishūsai Yagyū and In'ei Hōzōin. When the two old masters were young men, they were hotblooded and vehement like him. They started to change their ways after meeting the master Hidetsuna Ise no Kami Kami'izumi, who didn't even need a weapon to fight because he was one with earth and heaven. The two old masters are an example of what would Musashi become if he follows the right path in life.
- Freudian Excuse: Bullied into submission by his abusive father, Takezō spent his younger years filled with fury, and vented out his rage on those around him simply for the sake of doing so.
- Get a Hold of Yourself, Man!: Takezō endured a protracted version of this trope, with Takuan basically taunting him, berating him, and even hanging him from a tree for days, just to hammer into the boy's head that his life is not something to be wasted so foolishly.
- Handicapped Badass: Becomes this for a while after suffering a near-crippling injury to his right leg during the battle with the Yoshioka.
- Honor Before Reason: Zigzagged. Musashi is a Combat Pragmatist, and so doesn't normally care for traditional codes of honor when it comes to the battlefield. However, whenever someone challenges him, Musashi doesn't even consider the notion of running away, and even in defeat constantly seeks ways to better himself as a warrior. Gradually, he comes to view his opponents less as stepping stones towards his personal glory, and more as avenues to help better himself as a person.
- Hot-Blooded: Musashi's defining element in his early parts.
- Inferiority Superiority Complex: Musashi's initial goal is to become the greatest warrior in all of Japan, a title his father once held ("invincible under the sun"), and to this end, Musashi goes to various schools and faces his contemporaries simply to prove himself better.
- It's Not You, It's My Enemies: Though Musashi at times catches himself wanting Otsū to accompany him throughout his travels, the knowledge that he can die at any moment in his journey causes him to steady his hand.
- Living Legend: Eventually, Musashi's name becomes so well-known that samurai from far and wide come for his head in their own desperate attempts to claim glory.
- Lonely at the Top: Though Musashi tries to keep it under wraps, it's clear that he dearly misses Otsū's presence—but believes his journey to be of more paramount importance. Over time, he becomes more comfortable with his feelings towards Otsū and even outright acknowledges feeling wistful without her, expressing regret over always causing her to worry for him.
- Love Is a Weakness: Musashi gradually grows more and more drawn to Otsū as the story goes on, and on numerous occasions has expressed how he feels that his desires for her (both sexual and romantic) are detrimental to his quest, if not outright perverse. But with Character Development he comes to accept his feelings towards her and even express some regret that his years-long quest to better his skills has ultimately been time spent being separated from the woman he loves.
- Meaningful Rename: at the start of the story he goes by his birthname, Takezō Shinmen. Some time later the monk Takuan makes him turn his life around, and renames him Musashi Miyamoto: "Musashi" is an alternate reading of the Japanese characters of "Takezō", and Miyamoto due to Miyamoto village being Musashi's birthplace.
- Mook Horror Show: The Yoshioka battle, full stop.
- No Badass to His Valet : Musashi comes across as either a savage killer or peerless warrior, depending on who you ask, but his Trickster Mentor Sōhō Takuan sees him for what he really is: A frightened, confused youth with something to prove. Despite how easily he could maim or murder the monk, Takuan continuously criticizes and taunts Musashi from their very first meeting, utterly unfazed by the latter's empty threats. This is also the case with Otsū, as while Musashi can easily cut a man down without a second thought, Otsū really only sees him as her childhood friend Takezō.
- No Social Skills: Musashi has trouble relating to the trials and tribulations faced by non-samurai, and his determination to better his own swordsmanship confuses him on his own feelings at times. He's ignorant of Otsū's desire to get closer to him, and can't go five minutes of having a decent conversation with another swordsman without challenging him to a fight. He grows out of this when he decides to humble himself, helping an entire village farm their crops without resorting to violence or unnecessary cruelty in order to get the job done.
- Nominal Hero: The story doesn't really try to frame Musashi as necessarily heroic, and a lot of his more gruesome actions in the heat of battle (such as his slaughters when he is the target of a manhunt at the start of the story, or later the extermination of the entire Yoshioka clan) are presented as bluntly and brutally as possible.
- Oedipus Complex: He had a complicated relationship with his father, Munisai Shinmen, to say the least. Takezō tried to kill him several times as a child, and as a young man he becomes obsessed with surpassing him. He eventually overcomes the haunting memories of his father, when he defeats Baiken Shishido.
- Old Master: In'ei and Sekishūsai are this to him, learning a lot about life from them, and even becoming literally Spirit Advisors later in the story.
- On the contrary, his own father Munisai Shinmen was an Evil Mentor, hurting him physically and psychologically. In the early parts of the story, Musashi would stop what he was doing and would get lost in his memories of his father and how he mistreated his own son. He finally moves on after defeating Baiken Shishido.
- One-Man Army: Musashi cuts down about seventy highly trained and nationally respected Yoshioka swordsmen — that is, the entire school membership, after diving right into their center at the start of the conflict and mortally wounding their leader. This single-handedly catapults him to a national figure and doubles as a Crowning Moment of Awesome.
- Running Gag: This iteration of Musashi retains his real-life counterpart's infamous tendency to arrive extremely late to set duels; here, it's explained that Musashi doesn't do so intentionally. In his rematch against Inshun, he was late because he literally overslept; in his duel against Denshichirō, he was threatened at gunpoint by Ryōhei Ueda on the way there.
- Single-Target Sexuality: Otsū's the only one on his mind, even after years of his own deliberate separation from her.
- Slasher Smile: In his younger years, Musashi's love for intense mortal combat would make itself clear on his face. He slowly grows out of using it when he comes to recognize the weight of violence and slowly begins moving towards a Martial Pacifist route.
- Slipknot Ponytail: Sometimes during fights.
- Sociopathic Hero: Early on, Musashi's concerns lie heavily towards bettering himself as a warrior, and while he does care about other people (such as Otsū, Matahachi, and Jōtarō), it's clear that he treats everyone outside of those close to his heart is just either in his way or a new challenge. His learning empathy and compassion is one of the cornerstones towards his transformation into both a better samurai and a better person.
- Sore Loser: Zigzagged. Whenever he loses a fight, he makes every attempt to figure out how he failed and always pushes to better himself in every possible way. That won't stop him from being super salty about losing, however.
- Star-Crossed Lovers: Musashi and Otsū are mutually attracted to one another, and miss each other dearly, but thanks to Musashi's constant drive to better himself as a swordsman he and she are always driven apart. As Musashi comes to humble himself and understand the cost of violence, he becomes more comfortable with his feelings towards Otsū and plainly states how much he craves to be with her.
- To Be a Master: Deconstructed. His driving motivation is to become "invincible under the sun", but the closer he gets to achieving this goal the more realizes how little the title means, especially when his massacre of the Yoshioka school ends with him crippled and forced to crawl away past their already-rotting corpses.
- Took a Level in Badass: Keeps getting more and more Badass over the course of the series.
- Villain Protagonist: Starts off as an amoral thug, who challenges people to death matches for the sake of personal glory.
- Walking the Earth: Musashi lives as a vagabond, seeking out the strongest opponents all over Japan.
- Warrior Poet: He lives by the sword, paints, carves Buddha statues, practices calligraphy, engages in philosophical conversations and to top it all, he even learns farming.
- Wide-Eyed Idealist: Musashi's driven to become the strongest warrior in all of Japan, and to this end he overcomes obstactle after obstacle, never letting his failures overcome him and always working towards self-improvement as a warrior. It gets to the point where people are taken aback by his unnatural determination, some even calling him foolish for clinging to such outdated ideals. After his massacre of the Yoshioka school, Musashi comes to terms with the fact that even his desire to become the strongest ultimately makes him feel hollow, and so his Character Development leads him to stray away from bettering himself as a samurai to bettering himself as a person.
- Worth Living For: Though Musashi cares little for his own life and is perfectly content with losing it in a fine duel, the moment he thinks about Otsū, he gives everything he has to survive.
- Younger Than They Look: Many say that Takehiko Inoue draws Musashi in a way that he looks older. At the start of the story, when he is 17 years old, he looks like he's in his late twenties, due to his long limbs, tall height and big muscular frame (the Real Life Musashi Miyamoto is also said to have been a strongly built man even at an early age). A year later when he returns to Miyamoto village, he has let his facial hair grow and wears his hair loose, making him look like he is in his mid thirties. 30 volumes later, by the time he is in his late twenties, he looks like he is in his late fourties. That being said, Musashi's also noted by his fellow swordsmen for being considerably young for a man of his ambition and skill.
- Lampshaded by Akemi, who in chapter 2 says she thought he was 30 (he is 17).
- Justified because, in those times, people aged rapidly due to the harsh life and the lack of the technology complexity we have now.
Takezō's childhood friend who persuades him to leave Musashi village and join the war, thus setting of the events of the story. A decent person deep down, Matahachi continually lets himself and others down due to his very weak moral fiber.
- Butt-Monkey: He's a Dirty Coward through and through, and a petty, wretched lowlife to boot. His envy, self-pity, inferiority complex and laziness are his defining characteristics. Yet he's also a deeply frightened, guilt-ridden, self-loathing fool with a childhood of ostracism and an overbearing bully of an adoptive mother. Overshadowed by his best friend and spurned by his childhood crush after abandoning her for someone else, his entire life has been highlighted by inadequacy and misjudgment. He brings most of his own trouble on himself, but he's just a sad, weak man looking for validation in all the wrong places.
- Can't Catch Up: Not that he really tries anyway. Poetically illustrated in a visual leitmotif through the series: a recurring flashback shows Matahachi and Takezō as kids, they are running, but Takezō is getting far ahead and Matahachi is lagging behind.
- Character Development: Subverted time and again. For every opportunity the story throws at him to steer him towards the right path, he quickly gives in to his weaker qualities and ultimately makes life worse for himself. Finally played straight after the death of his mother, at which point he decides to become his own person without trying to measure himself to Musashi or anyone else. Also, when he's revealed to have been the Narrator All Along, he appears content with the fact that his audience is much more interested in Musashi's portions of the story than his own.
- Cowardly Lion: Tragically subverted. Whenever Matahachi is faced with a adversity or danger, he feels compelled to save the day or take a stand. He never actually does, and it haunts him every time.
- Crazy Jealous Guy: Despite the fact that Matahachi Really Gets Around, he finds himself constantly envious of Musashi and Otsū's relationship, and gets even more aggravated when he acknowledges that his cowardice is the reason Otsū and Musashi grew closer in the first place. This is defied by the time Musashi massacres the Yoshioka school; truly recognizing his own failures for the first time, Matahachi begs a sleeping Musashi to take Otsū with him throughout his travels.
- Dirty Coward: And it fuels his inferiority complex to Takezō.
- Foil: To Musashi naturally. They both start out at the same place. Musashi pursues martial perfection, often living like an ascetic and choosing to live in privation even when better options are available. On the other hand, Matahachi ends up wallowing in worldly pleasures, taking every advantage of every opportunity to make himself more comfortable.
- Glory Seeker: Leaves Miyamoto village and go to fight in the battle of Sekigahara to make a name for himself. He fails pretty badly.
- The Hedonist: Pretty much every time Matahachi sees an opportunity for immediate satisfaction, he takes it. It ends up biting him in the ass every single time.
- Inferiority Superiority Complex: He measures himself to Musashi constantly, to the point of depressing himself—when he sees just how dedicated Musashi is at trying to better himself as a warrior, it drives him insane that though the two of them literally grew up together, his own failures and weaknesses are ultimately what prevent him from making a name for himself. When his mother dies, he resolves to become his own person and follow his own path, refusing to measure himself in comparison to anyone else ever again.
- Legendary Impostor: For awhile he impersonates Kojiro, somewhat by accident, believing that the actual Kojiro is dead.
- Meaningful Rename: in a flashback, we see a middle-aged Osugi Hon'iden widowed and the folks wondering how the Hon'iden family will continue because she is childless. She asks a widowed vassal for his baby boy, Mataichi, and adopts him. She then renames him "Matahachi", with the hope that his horizons will expand, just like the character "hachi".
- Miles Gloriosus: He borrows Sasaki Kojirō's identity for a while to live off his reputation. It gets complicated when Kojirō himself shows up, and gets even more so when Kojirō leaves Matahachi for no good reason at all.
- Older and Wiser: Turns out later on that Matahachi's been the Narrator All Along, and as he narrates Musashi's tale appears nostalgic, humble, graceful, and not in the slightest bit the cowardly and hedonistic fool he'd been before.
- Pet the Dog: Matahachi's truly not a terrible person. He's just so desperate for validation of his own existence that he's willing to indulge in cruel or dishonorable acts to fill the void. It's clear, however, that he ultimately does care for those around him, and while the story frames his weaknesses as unfortunate characteristics, he's always presented with an opportunity to redeem himself.
- Narrator All Along: Once the story hits the point where Matahachi's mother dies, we flash forward to several years into the future, where it's revealed that an elderly Matahachi has been narrating his and Musashi's story to multiple people daily, for a fee.
- True Companions: For all of Matahachi's contempt and jealousy towards Musashi, it's clear that they're both inseparably tight friends and will always have each other's backs through thick and thin. This is best exemplified in the aftermath of the Yoshioka school massacre; even though prior to the battle, Matahachi and Musashi had a huge falling out, once the former finds the latter's cold and battered body lying in the soil, Matahachi lugs the man to medical care as quickly as he can.
- Unreliable Narrator: It's eventually revealed that an elderly Matahachi is actually the narrator of the story, and so it can be inferred that at least some parts of Musashi's story have been embellished for the sake of entertaining his audiences.
An orphan raised at the temple in Miyamoto village, Otsū is a childhood friend to both Musashi (Takezō at the time) and Matahachi. She was originally betrothed to Matahachi, but then he broke it off after he decided to run away with Okō and not return to Miyamoto village. She instead fixates on Takezō/Musashi (it's implied that he was actually the one she was in love with all along) and leaves Miyamoto to go after him when he heads out to make his name as a swordsman.
- Adaptational Badass: Otsū in the original novel was pathetic and needy, with a very weak constitution, often to the point of getting physically ill over emotional matters. In the manga, she is much more self-sufficient and even takes lessons in self-defense from the Yagyū.
- Arranged Marriage: Was originally betrothed to Matahachi, who in a moment of weakness ran off with another woman—essentially abandoning Otsū.
- Inelegant Blubbering: When Matahachi confesses his infidelity to Otsū by way of a letter, she goes livid to the point of crying and shrieking and biting herself in her anger and pain.
- Insistent Terminology: Continues to refer to Musashi as Takezō, long after he has officially changed his name.
- Silk Hiding Steel: Otsū is more than capable of fending for herself in the rather less-than-safe byways of Feudal Japan, especially after she takes some pointers from the Yagyū on how to defend herself.
- Single-Target Sexuality: Otsū is fixated on Takezō and won't give anyone else a second glance.
- Spirited Young Lady: Otsū's remarkable in the setting, as she very much manages to maintain the Yamato Nadeshiko trope she's supposed to fulfill—and yet more often than not defies that trope by being very outwardly emotional, loud, outspoken, and at times appearing uncultured. Yet her determination, beauty, purity of heart and earnest behavior more than make up for it.
- Yamato Nadeshiko: A bit more rugged than the usual version, due to her traveling, but many characters who meet her often comment on her poise and beauty, even in unusual situations.
- Adaptational Heroism: In the novel he sentences Takezō to three years of imprisonment before christening him Miyamoto Musashi.
- This is, however, implied in the manga as well, as after the scene where Takuan rescues Takezō and renames him Musashi, we get a Time Skip to when Musashi is 21 and arrives to Kyōto to have his first fight against the Yoshioka.
- Badass Pacifist: "He cut me down with his mind!!"
- Bullying a Dragon : A middle-aged Buddhist monk who mercilessly mocks, scolds and even challenges a violent young swordsman who practically leaves a path of corpses everywhere he goes. Most of his shenanigans are actually just an unorthodox approach to guidance, as he actively seeks to help Musashi realize who he really is, but that doesn't make it any less brazen. This is true to history, as Sōhō Takuan was respected by warlords and samurai for his frank, astute advice, but his acerbic honesty made him plenty of enemies as well.
- Cool Old Guy: In the manga he looks like he is in his late thirties-early fourties, but he definitely gives off this vibe.
- Ink-Suit Mangaka: Takuan is the manga's author, Takehiko Inoue, inserted in the story! Seriously, look how he was drawn with quite a resemblance to Inoue.
- Trickster Mentor: To Musashi.
Musashi's rival. A deaf-mute but prodigious young swordsman.
- Adaptation Deviation: The historical Kojirō was rumored to be fully or partially deaf in one ear, though nothing of the sort was suggested in the Eiji Yoshikawa novel. Vagabond is loosely inspired by history and the novel, but deviates heavily from both in that Kojirō is completely deaf and mute.
- Kojirō or characters based on him are often displayed with some form of malady. Ukyo Tachibana of Samurai Showdown is based on Kojirō, and appears to suffer from tuberculosis.
- Accounts of the historical Kojirō are so wide-ranging it's hard to portray him without this trope! His age is given as anywhere between 18 and 50 when he fought Musashi on Funashima; his trademark weapon ranges from the Drying Pole of the manga and novel to the shikomitsue (cane-sword); there is even some doubt over whether his name was Sasaki Kojirō at all.
- Adaptational Heroism: In the novel, Kojirō is much darker than his happy-go-lucky Manchild counterpart. The original novel portrays him as cunning, sadistic, and borderline psychopathic, although courageous and not without nobility.
- Blood Knight: He shares Musashi's intense love of combat, and constantly is in search of enemies as strong as himself if not stronger to better his swordsmanship.
- Bunny-Ears Lawyer: The only reason Kojirō's survived as long as he has is because of his incredible prowess with a katana. He's so good with it that his reputation alone was able to spread his name across Japan even before he was given the certificate which would formally establish his status as a samurai.
- Character Focus: The first arc featuring Kojirō took up about a third of the then-twenty volume series by the time it was done.
- Chick Magnet: Receives a lot of female attention even at a young age, and is frequently caught in women's beds by other characters.
- Die or Fly: Was on the receiving end of this by Ittōsai Itō, who only believed Kojirō could truly hone his skills as a swordsman through rigorous combat and extreme conditioning. As such, Ittōsai left Kojirō to face hundreds of hungry, bitter villagers in the middle of a vast valley alone and waited to see if he'd make it. He came back, as one of the deadliest swordsmen in all of Japan, and the first thing he did was defeat and cripple Ittōsai.
- Disability Superpower: Kojirō can't hear nor speak, and it's implied he has some unspecified disorder which prevents him from interacting with others properly. However, he compensates for all of that by way of his incredible swordsmanship—his lack of hearing forced him to become extra-perceptive to both his environment and his reflexes, enabling him to survive countless near-death scenarios by way of him simply being that observant.
- Dissonant Serenity: Several characters note how Kojirō's eyes almost never change emotion even in the face of certain death or extreme pain. Others note how when it does change emotion, said emotion is almost always excitement. Granted, he does display pain when he suffers horrible wounds (as any warrior would), and the one time he really breaks down is when Ittōsai leaves him to fend for himself against dozens of sword-wielding villagers hungry for his blood.
- To Miyamoto Musashi. Kojirō's a happy-go-lucky Manchild who can easily win the love of an entire village within a day; Musashi's mature, aloof, gruff, and doesn't tend to socialize at all (unless they happen to be particularly skilled swordsmen). Kojirō constantly goes after women without rest, while Musashi's fixated singularly on Otsū. Kojirō grew up loved by his father-figure and was treasured in his community, while Musashi grew up constantly being manhandled by his abusive father and ostracized by those who saw him as a "demon child." But both Kojirō and Musashi love using their swords in battle, are always restlessly searching for opponents to spar with all in the name of bettering their own skills, and are so deeply connected to the sword that the two of them can hold a conversation practically just by swinging sticks at each other in place of blades. Their passion for the sword is the one thing the two have in common.
- Genius Bruiser: He is so perceptive and attuned to the sword that he can learn entirely new techniques in the midst of battle.
- Handicapped Badass : Deaf, mute, and easily one of the most talented and lethal swordsmen in the entire series, which is saying a lot.
- Happily Adopted: Kojirō deeply loves and respects his Parental Substitute Jisai Kanemaki, to the point that when he learns the definition of the word "strong", his mental image is that of Jisai himself.
- Hyper-Awareness: His skills are on-par with Musashi's, if not outright surpassing them, and it's thanks to his ultra-perceptive nature that he's been able to survive multiple gory battles throughout Japan.
- I Want My Mommy!: When Ittōsai leaves Kojirō behind to fend for himself in a Die or Fly sort of test against dozens of hungry, angry, violent villagers, Kojirō looms over all the corpses he's made and breaks down, calling out for Jisai as he sheds tears of pain and fear.
- Idiot Savant: Terrible in social circles and lacking in virtually all forms of etiquitte, but if you hand him a sword he'll cut you down without a second thought.
- Manchild: He's very socially unaware and does things impulsively. Characters are frequently frustrated at his disregard for societal norms.
- Moses in the Bulrushes: Kojirō is introduced in this fashion. His father had him sent by boat from a besieged castle to be raised by his former master, Jisai Kanemaki. His mother had been swept overboard and killed during the voyage and he would have suffered the same fate if Jisai hadn't saved him.
- No Social Skills: People are always impressed by Kojirō's swordsmanship, but outside of combat and sex, Kojirō's not really good at many other things like writing, etiquette, and empathy.
- Odd Friendship: For all his and Musashi's differences, the one thing binding them together is their shared passion for the sword, and their deep understanding of the way of the sword. The two even hold what is essentially the equivalent of a conversation by swinging sticks at each other in a mock-duel.
- The Unintelligible: Ninety percent of his dialogue throughout all of his appearances consist of Auuu, Aaa, or some variation of the two. Justified, given that he's deaf and mute.
- What Beautiful Eyes!: Random robbers have been struck by thoughts of how Kojirō's eyes look beautiful and too innocent for him to have killed anyone. There is a lot of focus on his eyes in general, as being deaf has led to him having very sensitive, perceptive eyesight.
- Worthy Opponent: Rather tellingly about his attitude towards the sword, Kojirō views those who are unwilling to give their lives in a battle as unworthy of his time. The two people he holds deep respect towards are Musashi and Jisai Kanemaki—the latter of whom Kojirō outright upholds as "strong."
A young orphan boy and Miyamoto Musashi's first apprentice.
- Adaptation Deviation: Jōtarō's character is very faithful to the novel, although Inoue's Jōtarō is an orphan; Yoshikawa's is the son of disgraced samurai Aoki Tanzaemon (named only as 'Captain Aoki' in the manga, and with apparently no connection to Jōtarō.)
- The historical Miyamoto Musashi did have amongst his many followers a man named Aoki Jōemon, who appears to be the basis for Jōtarō (whose family name in the novel is Aoki.) Beyond these basic details, however, Jōtarō's and Jōemon's characters and lives are not at all alike. For the most part Jōtarō appears to be a creation of the original novel's author, Eiji Yoshikawa, inspired by Jōemon but not really a representation of him, as is the case with with other characters like Musashi, Kojirō and Takuan.
- Given the historical Musashi had two adopted sons (Mikinosuke and Iori) and the fictional Musashi takes two boys as disciples (Jōtarō and Iori) in the novel and manga, it is possible Jōtarō took some small inspiration from Mikinosuke.
- Bratty Half-Pint: To an extent. Jōtarō is generally a loyal and good-hearted kid, but he does have a bit of a smart mouth on him and no qualms about talking back to his elders.
- Ventures close to Mouthy Kid territory at times, when he calls out the adults around him for their poor behaviour.
- Foil: For Musashi. Though not violent or aggressive by nature, Jōtarō's free-spirit and idealistic image of being a samurai resemble a young Takezō. Otsū even remarks on their similarities when she and Jōtarō first meet. Jōtarō occasionally shows the same reckless disregard for his own life. The Yagyū men even refer to him as a 'Demon-Child' after he kills the Yagyū family dog Tarō in revenge for mauling him, an epithet once reserved for Takezō.
- Kid Samurai: Bokuto 'n all! And given the novel was written in the 1930s, Jōtarō might well be the Trope Maker.
- Kid Sidekick: To Big Brother Mentor Musashi and Otsū
- Never Be Hurt Again: How Jōtarō came to be orphaned is unknown, but he is clearly insecure about abandonment. He tearfully expresses his desire to become strong enough to not rely on others to Musashi: "I have to be able to survive by myself... Without anyone's help. I have to be strong. That's why I want to be your disciple... That's why I want to become a samurai...!!" Seeing his own feelings of abandonment and un-belonging reflected in the boy seems to be what convinces Musashi to take him on.
- Parental Abandonment: In 'Vagabond' Jōtarō is an orphan, although whether by abandonment or bereavement is not stated. The innkeeper he worked for (and presumably acted as his guardian) basically kicked him out and told him to leave and follow Musashi. On top of that, Musashi himself is not the most reliable Parental Substitute...
- Prone to Tears: Poor Jōtarō! Under that smart-mouthed, bratty facade is pretty sensitive boy. It's hard to blame him given how he has no home or family and keeps getting abandoned...
- Often turns into Inelegant Blubbering.
- Tag Along Kid: Travelling with Musashi and Otsū in a world of swordsman, warrior-monks and bandits, Jōtarō certainly qualifies as this.
- The Apprentice: He's Musashi's only disciple until Musashi later takes on Iori.
- Wide-Eyed Idealist: A young boy desperate to be a samurai, Jōtarō has a very idealised view of what it means to be a warrior and a man.
Osugi Hon'iden (Matahachi's mother)
The cantankerous and tyrannical matriarch of the Hon'iden family. Sworn enemy of Musashi and Otsū.
- My Beloved Smother: And how! Osugi dotes over Matahachi, dogs his every step, berates him and guilt-trips him, and yet refuses to believe him guilty of any wrong-doings to the point of delusion, projecting all blame onto Takezō/Musashi and Otsū. And through it all she remains blind to her son's own repeatedly self-destructive cries for help and her own part in his misery.
- The Resenter: She blames Takezō/Musashi and Otsū for every ill that befalls Matahachi, her and her family in general, and will no hear otherwise.
- Revenge Before Reason: Her utter hatred of Musashi and Otsū and need to punish them blinds her to the fact they've done nothing to wrong her or her family.
- Screw Politeness, I'm a Senior!: This. In Spades.
- Selective Obliviousness: Refuses to acknowlegde that Matahachi was the one who betrayed Otsū.
Munisai Shinmen (Musashi's father)
- Abusive Parents: He was a piece of work. A large part of Takezō's initial motivation to become strong is fuelled by his desire to escape his father's shadow, as Munisai routinely shamed him out of fear that one day the boy would usurp his place as the so-called strongest warrior in all of Japan. Even after Munisai's death, the shame and fear Takezō felt under his grip drove him to seek strength well into his late teen years, to the point where he willingly participated in the Battle of Sekigahara to make a name for himself.
- Crazy-Prepared: As young Takezō learns the hard way when he attempts to attack Munisai in his sleep, only for him to wake up immediately and pull a spear from under his covers. This is actually not as eccentric as it sounds, as it was not uncommon for samurai and lords to sleep with a makura yari, or "pillow spear" within their reach in case of just such a threat.
- Posthumous Character
The second generation master of the Yoshioka school of swordfighting in Kyōto, successor to his father Kempō Yoshioka. While a superbly talented swordsman, he is also hedonistic and carefree, though he can and will be serious and take appropriate measures in times of crisis.
- Adaptational Badass: In the novel, he really is little more than a hedonistic pretty boy, who is actually inferior to Denshichirō in swordsmanship.
- Aloof Big Brother: A prodigy of a swordsman with natural skills, he is somewhat cold to and talks down to his younger brother Denshichirō, who does not have his natural gifts and struggles in Seijūrō's shadow.
- Arrogant Kung-Fu Guy
- Big Brother Instinct: While he remains an Aloof Big Brother, he still ultimately cares for Denshichirō. He even tries to kill Musashi in a sneak attack to prevent him from fighting Denshichirō, having already known that Musashi would win... unfortunately for Seijūrō, Musashi had surpassed him too.
- Combat Pragmatist: Not above ambushing people. See Big Brother Instinct. It's revealed by Ueda that Seijuro's father told him to only fight those whose defeat is certain.
- Crouching Moron, Hidden Badass: First appears as a drunk pretty boy chasing women in the street and tickling them...before drawing his sword and pointing it at Musashi's throat faster than he can even react.
- Fragile Speedster: The fragile part is downplayed somewhat, but he's a short and skinny swordsman who is incredibly quick (even after all his trials and fight experience, Musashi still can't actually dodge Seijūrō's fastest strikes, only react just enough to turn what would have been lethal blows into wounds instead), who simply is not built to take punishment the way Musashi or his brother can.
- The Hedonist: Prefers spending time in the pleasure quarters over running his dojo, and enjoys drinking sake.
- Hidden Depths:
- Although he appears as carefree, pleasure seeking wastrel, he is a deadly fighter. He hates the pressure of living up to the Yoshioka name and looks for every opportunity to ditch it or to make people not expect that from him.
- While seemingly happy to tease and torment his younger brother, in private Seijūrō admits that ha actually cares a great deal about Denshichirō and worries about his safety. Furthermore, after being killed by Musashi, it's shown that there are a great number of scars on his body, and Ryōhei instantly deduces that Seijūrō has likely secretly fought off many other threats to the school and Denshichirō the same way he attempted to do with Musashi.
- Iaijutsu Practitioner: When Musashi first encounters Seijuro, he marvels at how fast Seijuro's draw is.
- Older Than They Look: Just looking at him, you would not consider him to be the oldest of the Yoshioka brothers. Toji even mentions that people tend to think he and Seijuro look younger than they are.
The second son of Kempō Yoshioka. Although he lacks the innate skill of the prodigy Seijuro, Denshichiro is devoted to his training and is much more involved with the Yoshioka School than Seijuro.
- Adaptational Badass: In the novel, while he was considered the more competent of the two brothers, Denshichirō wasn't all that much better than Seijūrō overall.
- The Big Guy
- Big Little Brother: Towers over his smaller and thinner older brother Seijuro
- Can't Catch Up: As hard as he works he can never match Seijūrō in swordsmanship. And in the year leading up to their rematch he utterly fails to keep up with Musashi, who makes the most of the year and grows into one of the very best swordsmen in the land.
- Happily Married: Shown briefly to be a devoted father and loving husband.
- Honor Before Reason:
- He insists on fighting his rematch with Musashi even though he is clearly outmatched and stands nothing to win.
- He also expels Ryōhei Ueda, his de facto brother, for trying to protect him by arranging for Musashi's demisenote .
- Over Shadowed By Awesome: Skilled and dedicated swordsman, but hopelessly outranked by his brother and eventually Musashi as well.
- Sibling Yin-Yang: Very much so. Seijūrō is a carefree pretty boy blessed with supreme talent and confidence, and Denshichirō is a stern, hulk of a man, who works hard trying to be as good as his brother.
A senior disciple of the Yoshioka School. He was raised by the Yoshiokas and is almost regarded as a brother to Seijūrō and Denshichirō.
- Combat Pragmatist: Hopes to ambush Musashi rather than fight honorably.
- Like a Son to Me: Kempō Yoshioka considered him his third son.
- Spirit Advisor: Becomes one to Otsū and Musashi, albeit not in a positive way: he still holds grudges for the demise of the Yoshioka clan, and his ghost pops up to torment both of them.
- Stiff Upper Lip: His trademark attitude is smoking his pipe and ponder. He is introduced this way when Musashi first comes to the Yoshioka dojo and is killing many disciples. But this attitude becomes truly evident during the Battle of Ichijōji, when he is seriously wounded with half of his face cut and he rests under a tree, calmly smoking his trademark pipe while ravens flock to eat his flesh.
- 10-Minute Retirement: He is expelled from the Yoshioka school by Denshichirō, but later when Denshichirō dies fighting against Musashi, Ueda reads Denshichirō's will which declares that, in case that Denshichirō dies, Ueda is readmitted to the school and made headmaster.
Another senior disciple of the Yoshioka School, Toji considers himself the personal disciple of Seijuro and arrogantly believes that Seijuro is the greatest swordsman in the world and that Toji is second only to Seijuro himself. After Musashi's first clash with the Yosjioka, Toji goes on a self-appointed mission to kill Musashi.
- Always Someone Better: Prior to the start of the series, he truly believed that only Seijuro was better than him. Inshun easily dodging his attack and Toji realizing that he wasn't quite as high up on the warrior's pecking order as he believed was an enormous blow to his ego.
- An Arm and a Leg: Toji loves this trope. Swinging for the wrists of his opponent and chopping off their hands while they're attacking him is his favorite technique.
- Awesome Ego: [In-Universe] None of the other senior Yoshioka disciples can stand him because of his arrogance, but he is an excellent swordsman. After his death several of the senior Yoshioka apprentices admit that they could only dream of matching Toji's skill with a sword.
- Back for the Dead: After being absent from the story for a long stretch of time, he reappears as a dirty wanderer. Hearing the news that Musashi killed Seijūrō, he launches a reckless suicide attack on Musashi, and is cut down in a single move, highlighting exactly how much Musashi has improved.
- Blood Knight: More than most, even among the bloodthirsty cast of this manga. One scene hints that he might get an actual sexual thrill out of combat.
- Break the Badass: His entire ego and sense of self-worth is built around his ability as a swordsman, so the realization that that Inshun would have easily defeated him is a shattering blow to his confidence and ego. Failing to kill Musashi doesn't do his pride any good either. He never returns to the Yoshioka, and when he finally reappears in the story, he's a mess from a year of homeless wandering.
- Dueling Scar: Toji has a long, straight scar on one side of his face. While the source of it is never explained, it's implied to be from either a sword fight or training.
- I Have No Son!: After his death one of the Yoshioka goes to inform his mother. She denies being related to him.
- Lightning Bruiser: He isn't as fast as Seijuro, but he's extremely quick while being considerably larger than the diminutive Seijuro.
- The Rival: He's a self appointed rival to Musashi, having vowed to catch and kill Musashi after Musashi endangers the reputation of the Yoshioka by defeating multiple students.
- Smug Smiler: A constant smug smile is his most prominent trait.
Tropes shared by the Hōzōin monks:
- Warrior Monk: The monks of the temple all practice the spear and have a formidable reputation as a result.
The first generation master of the Hōzōin spear technique. Has retired from teaching the spear technique and now lives as a farmer near the temple.
- Call to Agriculture: He has retied from his position as the master of the temple and now just humbly lives on a farm.
- Old Master: A tiny, wrinkled old man with decades of combat experience. Although he no longer breaks out his fighting ability, he still has it and is a
- Retired Badass: Once was a great spear master and martial artist, now he just peacefully tends to his fields and tries to teach Inshun.
The second generation master of the Hōzōin spear technique, and current leader of the temple.
- Arrogant Kung-Fu Guy: Not as much of Jerkass about it as some others, but he certainly doesn't hide his supreme confidence in his own abilities.
- Blood Knight: As with many of the most prominent fighters in the series he loves to fight strong opponents.
- Laser-Guided Amnesia: When he was a boy, Inshun's father was visiting the temple as part of a warrior's pilgrimage, until a random wandering ronin attempted to rape Inshun's mother. All three adults died in the ensuing fight, leaving a traumatized Inshun to be adopted by the temple, particularly In'ei. Inshun has no memory of this whatsoever until his loss and near death at Musashi's hands in their second bout makes him recall it all.
- Meaningful Rename: His birthname is Shinnosuke Mitsuda, and he belonged to the Mitsuda samurai family, but he gets orphaned when a bandit rapes his mother and kills both of his parents. Afterward In'ei adopted him and, using the first character of his name, renames him "Inshun".
- No Social Skills: He is aloof and cool to his peers, to the point they come to resent him. There is absolutely no malice in this, and Inshun frequently even comes across as somewhat jovial, but he simply has no idea how to talk to other people and socialize successfully.
- Near-Death Clairvoyance: His near death experience in his second bout with Musashi helps him unlock repressed memories.
- Slasher Smile: Frequently sports a smile at all sorts of inappropriate times. Doing so during or just before combat can make it come as this trope.
- Wake-Up Call Boss: After fighting Inshun it really dawns on Musashi that there are still fighters much stronger than him.
A skilled spearman of the Hōzōin. He takes pride in his ability with the spear, but is otherwise reserved and respectful to In'ei and Inshun.
- Catchphrase: "You have had/will have the privilege of being defeated by Agon of Hōzōin."
- Spared By Adaptation: In the original novel, Musashi never fights Inshun, but ends up killing Agon with a single blow... with a wooden sword no less.
- The Stoic: A calm, reserved monk who doesn't readily display his emotions.
- You Are Not Alone: Agon confesses that, despite the antipathy that Inshun generates in the rest of the students, he still wants to be friends with him.
- Professional Butt-Kisser: Towards In'ei
- Smug Snake: Thinks a lot of himself, but his skills lie in playing politics, not in matters of combat or religion. When Inshun discovers and confronts his conspiracy among the other monks to displace Inshun, the young warrior monk whips all the treacherous ones by himself.
- The Starscream: He wants to supplant Inshun as the second generation master of the Hōzōin
- Badass Pacifist: Holds Musashi off with a backscratcher while bedridden and completely saps Musashi of his will to fight without even being fully conscious at the time.
- Heroic Neutral: The Yagyū clan have always kept out of the conflicts of the greater clans.
- Old Master
- Obfuscating Insanity : A light example. He has become a bit absent-minded and strange in his old age, but he's seemingly every bit as sharp as he was in his prime, still as dangerous as any young swordsman and certainly much wiser than the majority of the other characters. Observe how he defended himself from Musashi in his sleep and stared down the vicious swordsman Ito Ittōsai, deterring both without even having a sword on his person. The trope only is played straight on his deathbed, when his mind genuinely begins to slip.
- The Magnificent: Other swordsmen consistently refer to him as "the invincible Sekishūsai".
Sekishūsai's favorite grandson and heir.
- The Ace: it is recurrently said that he is one of the best fighters in the series, but we never get to see Hyōgonosuke in a fight, thus this becomes an Informed Attribute.
- Heir to the Dojo:
- Really Gets Around: he likes to indulge in sexual pleasures, much like Matahachi, Seijūrō and Kojirō.
An old, retired swordsman who's washed up and raises Kojirō as his son after his parents die.
- Ain't Too Proud to Beg: He's so devoted to Kojirō that begging the villagers for food doesn't bother him.
- Badass Decay: [In-Universe] In his past Jisai was a Master Swordsman, considered such a great master that his young pupil Ittosai wept at the knowledge that he could defeat Jisai, because Ittosai feared that meant there would be no challenges left for him as a swordsman. When we first see him in the narrative, he's a broken down, burnt out wreck of a man that lives in extreme poverty and can't bring himself to take up the sword again.
- Took a Level in Badass: Eventually, he recovers some of his thunder during (and to a lesser extent, after) the fight against Yūgetsusai Fudō.
- Combat Pragmatist: it seems that the Chujō-ryū that Jisai teaches has plenty of techniques designed for pragmatic and ruthless use in combat. Ittōsai points out the irony that while Jisai claims to be trying to use these techniques against Kojiro to discourage Kojiro from taking up the sword, what Jisai is actually accomplishing is to give Kojiro the most intense and thorough training possible in how to counter all these moves that the other pragmatists of the world would use against him.
- Dented Iron: He takes a wound to his arm defeating Fudō, and is quick to note that he'll never fully regain use of his arm afterward. But even one handed he is a capable swordsman due to experience, trickery, and Combat Pragmatism.
- Humble Hero: He turns down the offer of a large, abandoned house as a reward for defeating Fudō, recognizing the danger of becoming the new savior of the village. He states that the little shack he shares with Kojiro suits them just fine. He also keeps trying to do odd jobs around the village in addition to teaching swordsmanship, and apologizes when he's unable to do tasks due to his arm injury.
- Nervous Wreck: Jisai's nerves were shattered in battle, likely due to being defeated by his former student Ittosai. The villagers initially write him off as a coward and think he's pulling a scam when he tries to open up a sword school as a last ditch effort to avoid poverty. When he volunteers to fight Fudō, they note that Jisai keeps hesitating, and basically every few steps along the way, as he basically loses his composure, then has to force himself out of anxious paralysis repeatedly.
- Old Master: Though he's rather washed up at the time the story begins, he is eventually treated this way by the villagers after he saves them when he slays the villain Yūgetsusai Fudō. He explicitly refuses to teach Kojirō, wanting him to have a peaceful life, not that it stops him.
- Overprotective Dad: Refuses to teach Kojirō the sword time and again, fearing the day that Kojirō would be struck down in a meaningless battle.
- After Kojirō's win against Denshichirō, he concedes that the cosmos has bigger plans for him, and writes a certificate that lets Kojirō practice his sword style. However, as Kojirō leaves home before he can hand over the certificate, it becomes a McGuffin that has to be presented to him.
- Papa Wolf: His near paralysis at the thought of fighting again and facing Fudō ends the moment that he realizes that Kojiro may be in danger due to Fudō, and Jisai immediately and fearlessly charges into battle.
- Parental Substitute: To Kojirō.
A local youth from the village where Jisai and Kojiro lived, he initially bullied Kojiro for being deaf and mute, but became friends with Kojiro after Kojiro beat him in a fight. The two bonded over their interest in swordsmanship and becoming great warriors. Independent of the plan of other villagers, they attempted to slay Yūgetsusai Fudō together, and after surviving the encounter, he studied swordsmanship under Jisai.
- Blood Brothers: He has this relationship with Kojiro.
- Defeat Means Friendship: He bullied Kojiro at first, but the two became friends after Kojiro was able to defeat him.
- Mistaken Identity: With his final breaths he tries to implore Matahachi to take Jisai's scroll and give it to Kojiro. Matahachi mistakenly believes that Tenki is Kojiro and the scroll belonged to him.
- Overshadowed by Awesome: In Jisai's new school, Tenki becomes a formidable swordsman, the second best of Jisai new batch of official and unofficial pupils. The first, however, is Kojiro, who is far beyond him.
- Reformed Bully: As a boy he bullied Kojiro and was the leader of a group of other boys. As a young man and an adult he is never shown being anything but kind to people.
- Rugged Scar: Fudō permanently scarred his face when he and Kojiro attempted to kill the crazed samurai. It gave him a suitably badass look when he later became a swordsman.
- "Shaggy Dog" Story: His attempt to find Kojiro and bring him the certificate of swordsmanship ends in this. While traveling near a castle under construction, he is mistaken for a spy and killed by the local soldiers. He can only leave the certificate to Matahachi in hopes that it will somehow reach Kojiro after his death.
- They Call Him "Sword": He invoked this trope by choosing to call himself Tenki Kusanagi. The Kusanagi-no-Tsurugi is a legendary Japanese sword considered one of the greatest treasures of Japan, making it roughly to equivalent to someone from England setting out to become a great swordsman and changing his last name to Excalibur.
A warrior who lost his mind and left behind his life as a samurai, he now lives as something of a hermit in the same backwoods farming village as Jisai and a young Kojiro. Fudō is no harmless old hermit however, as he essentially extorts the village into providing him with food, alcohol, and their daughters too, and easily slaughters anyone who might try to oppose him.
- Ax-Crazy: Fudō is definitely not right in the head. He's also a dangerous swordsman who could easily overcome even multiple villagers ganging up on him.
- Cloudcuckoolander: Fudō has a lot of odd mannerisms, speaks to himself in odd ways, does things like forget to take his sword with him when Kojiro and Tenki set fire to his hut and then calmly walks back into the burning build to retrieve it, barely react to the loss of his hand, etc. Considering the rest of his character, it's chilling and unsettling, because nobody knows how he's going to react or overreact to something at any time.
- Covered with Scars: He has multiple large scars from old wounds on his arms and torso.
- Fallen Hero: The villagers mention that at one time Fudō was the savior of the village who rescued them from ravaging bandits, but he fell into madness, no longer protects it from outsiders, and forcibly takes whatever he wants from the villagers.
- Major Injury Underreaction: He more or less takes his hand being cut off in stride after the initial surprise.
- Retired Badass: A dark version of this trope. A badass swordsman living his twilight years as a recluse in a tiny village... which he terrorizes with his potential for violence, taking whatever he wants, and forcing them to send the local girls his way as soon as they come of age. After seeing his capabilities as a fighter (in particular how quickly Fudō adjusted to wielding Kojiro's long sword one handed), Jisai speculates that Fudō might have once been a famous warrior under another name.
- Starter Villain: The first major antagonist Kojiro tries to face... and he's actually too much for a young and completely untutored Kojiro to handle, despite Kojiro getting in a lucky blow that takes off one of Fudō's hands. Jisai has to step in to save his adopted son.
A famous swordsman and former student of Jisai.
- Animal Motifs: Ittōsai thinks of himself as a tiger. Both Mushashi and Sekishūsai liken him to a bear. Both are large, solitary, highly dangerous apex predators, so both are apt comparisons.
- Blinded by Rage: Downplayed somewhat. When he fights Musashi, Musashi is compensating for an injured leg by remaining still within a circle that he draws in the ground with a walking stick, and telling challengers that they can leave and Musashi will do them no harm, but if they enter the circle, Musashi will kill them. The circle is exactly as large as the reach of Musashi's sword, so it acts as a visual aid to Musashi, letting him time his strikes perfectly and make up for the fact that he has no mobility thanks to his lingering injury. Ittōsai immediately grasps the purpose of the circle, but he becomes so infuriated by Musashi refusing to meet his bloodlust and aggression in kind that he eventually charges into the circle, and takes a serious (perhaps even fatal) wound from Musashi doing so instead of finding a way to outsmart Musashi's stratagem.
- Blood Knight: Almost certainly the biggest example in the entire series, which is no small feat. Ittōsai lives only for battle and growing stronger, and seemingly has no other major interests in life.
- Broken Pedestal: Very downplayed, but as a child Musashi idolized Ittōsai and envisioned him as something like a demon god and aimed to follow Ittōsai's example. By the time that Musashi encounters him (aside from the brief encounter Musashi doesn't remember in the wake of Sekigahara), Musashi is trying to let go of his bloodlust/violent tendencies, no longer wants to be like Ittōsai, and the encounter seems to convince Musashi that he's taking the right path in doing so.
- The Corrupter: Acted as this to a young Kojiro. It didn't go the way he expected, and ended with Kojiro cutting off half of his right hand.
- Die or Fly: his teaching approach, much to the chagrin of Kojirō.
- The Dreaded: Between his skill in battle, incredible bloodlust, and complete amorality, he's likely the single most dangerous man in Japan. Everyone who knows his reputation treats him accordingly, aside from those swordsmen who are fearless/reckless enough that they want to either duel or learn from the legendary Blood Knight.
- Fashionable Asymmetry: When Musashi encounters him, not only do Ittōsai's clothes look very rough, but his left arm has the sleeve cut short, while the right has a long sleeve that completely hides his arm. This is partially the natural result of Ittōsai being a homeless wanderer, and partly to hide the crippling injury Kojiro inflicted to his right hand.
- Foreshadowing: When he first encounters an adult Kojiro in the wake of Kojiro and Jisai have one their sparring bouts, Ittōsai slaps Kojiro for not giving his all against Jisai, then is caught by surprise when Kojiro rushes him afterwards and gets the better of him in fisticuffs and wrestling for awhile. In spirit this is extremely similar to what happens after the end of Ittōsai's Die or Fly style training. Kojiro returns furious from where Ittōsai left him in the wake of Sekigahara, and catches Ittōsai by surprise in the fight that follows, resulting in Ittōsai losing part of his hand.
- Genius Bruiser: Not only does he have great physical strength even in his fifties, he is also very cunning. He even manages to completely change his fighting style to work around the crippling injury Kojiro dealt him.
- It's All About Me: While other characters start to seek deeper things in life the more the series goes on, he never seeks spiritual growth and calls Sekishūsai's "way of without a blade" nonsense.
- Sadist: At the very least he has no hesitation at causing pain, death, and emotional turbulence in others as part of his extreme Die or Fly style training. At worst he seems to relish it.
- Shadow Archetype: He embodies the very worst of Musashi's early bloodthirstiness and obsession with battle and strength. Mushashi crosses paths with Ittōsai right around the time Musashi begins to put all of that behind him, although Ittōsai nearly makes him revert to his old self.
- The Sociopath: Ittōsai is utterly amoral. Good and evil effectively don't exist for him, only battle and the sword.
- To Be a Master: He lives an extreme version of this lifestyle, only caring about being the strongest in the world.
- Uncertain Doom: He's wounded in his fight against Musashi, and while he manages to walk away, it's clear that the wound is seriously bothering him, as he collapses not long afterward and is last seen laying under a tree. It's left ambiguous if he dies from the wound (or an infection setting in afterward) or not.
- Walking the Earth: Ittōsai wanders endlessly in search of battle and mastering the sword.