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Tadashi Hamada (浜田 正 Hamada Tadashi) is the tritagonist in Disney's 2014 animated feature film Big Hero 6. A gifted robotics student at the San Fransokyo Institute of Technology, Tadashi is the creator of Baymax: a robotic, personal healthcare companion, like he states himself.

An accident caused by a mysterious fire catalyzes the events of the film, leading Hiro, Baymax and Tadashi's best friends to band together to investigate the "accident" and catch the culprit responsible.


Tadashi was an inventor and the older brother of Hiro Hamada. The Hamada boys were taken in by their aunt Cass some time after the death of their parents, where they were raised in her café in the city of San Fransokyo. While Hiro was unable to remember their parents due to his young age, Tadashi possessed a clear memory of what they were like. During their childhood, Hiro exhibited high intellect for his young age, although Tadashi was the only person to fully understand how he felt due to the boy's intelligence isolating him from friends. They also came up with a special set of rules that only they knew.[2] On Halloween days, Tadashi also took his brother to haunted houses.

By the time Hiro graduated from high school at the age of 13, Tadashi was accepted into the prestigious San Fransokyo Institute of Technology, where he became friends with Go Go Tomago, Wasabi, Honey Lemon and Fred.

On the last Christmas before his death, Tadashi built a Snow Machine because it didn't snow where they lived. The machine malfunctioned and caused an avalanche, but Tadashi kept it as he intended to fix it and give it as a present for Hiro next year.

During his time studying at SFIT and majoring in Robotics under the tutelage of Professor Robert Callaghan, Tadashi earned his own laboratory through hard work—a lab that belonged to a former student, Bob Aken, a few decades before. Tadashi admired Callaghan, but also became a fan of SFIT graduate Dr. Trevor Trengrove as he read Trengrove's groundbreaking thesis about artificial intelligence titled "Artificial Fun-telligence"[note 1]. Tadashi owned a copy of this thesis and became inspired by it, as well as his desire to help people, to start his very own project about a healthcare companion robot that would help anyone in need. He named his project "Baymax" and went through 84 attempts until the robot was perfected. Tadashi recorded each test, and although at times he felt tired or desperate that Baymax wasn't working the way he wanted, he never gave up as his motivation was to help as many people as he could. Since Tadashi was not an expert in the medical field, he asked fellow student Lily for help to code a healthcare chip with a large database of nursing information for Baymax that allowed him to hold most kinds of information—including memories and a personality of its own.

After the final test, Tadashi was excited and wanted to show Baymax to Hiro, though he first introduced the robot to Aunt Cass and his friends. Tadashi also participated in a seismic project for SFIT where he created a model of a building that would support huge earthquakes, and Baymax learned about this.

However, Hiro, not wanting to attend college himself because he considered it a waste of time, soon became involved with bot fighting, to the displeasure of Tadashi who believed that Hiro was wasting his potential when he could do something useful with his gift. Due to this new problematic behavior, Tadashi had sewn mini-GPS systems into every one of Hiro's hoodies to keep track of him.[3]


Tadashi is a tall, slender, slightly muscular teenager of a larger build than others in his family. He has large, warm brown eyes and neat black hair cut above his prominent ears. His face shape is different from those of his aunt's and brother's, with a longer face, larger jaw, and slightly larger nose.

His most notable physical trait is his preference for a black baseball cap with a red-and-gold San Fransokyo Ninja lettering on it. He is rarely seen without this cap in the film, except for a few scenes such as when he takes off his moped helmet, and it is also off in many family photos that can be seen.

Tadashi's main choice of apparel is based off of a smart-casual type of fashion, which is usually neat, conventional, yet relatively informal in style. His choice of outfit and color-coding reflect his personality, smart yet vibrant and full of energy. Since he changes his clothes daily, he does not wear any one outfit for much longer than others. However, he owns many similar articles of clothing, only varying in color. He owns several blazers, crew-neck t-shirts, and cardigan sweaters, usually in the colors white, black, tan, red, or various shades of green. He often wears mint-colored sneakers with white soles and shoelaces and occasionally carries a tan satchel across his shoulder.

When he introduces Hiro to his friends, he is wearing a white crew-neck t-shirt with an artwork of a SFIT ninja mascot, along with a grey cardigan, brown pants rolled up around his ankles and his mint-colored sneakers. He wears the same shirt to bed that night, with green plaid pajama pants.

On the day of his death at the San Fransokyo Institute of Technology Showcase, he wears an olive green blazer over a black shirt, with a similar pair of rolled-up brown jeans. Before he runs into the burning building, his hat falls off of his head, which Hiro retrieved and kept as a memento.


Incredibly kind, encouraging and hard-working, Tadashi is considered the epitome of a great brother, nephew and student, always there when people need him. He has an energetic sense of humor and can be silly and excitable.

Tadashi is very hard-working and intellectually gifted. He does not believe in "dead ends" and values hard work to accomplish goals. He also has a large understanding of health and medicine. Ever the optimist, he successfully balances this rising career in cutting-edge technology and providing moral and emotional support for his younger brother Hiro while keeping a good attitude and a happy smile. He also even appears to be athletic and he is known to have taught Hiro some karate; Baymax's statement that Tadashi was in 'excellent health' also indicates that he is physically fit.

As the only male figure in Hiro's life, he has carried the burden of responsibility from a young age, knowing that he had to lead Hiro and be a good role model. Having to care for Hiro alongside their aunt Cass has made Tadashi gentle and understanding, though as the big brother, he can still be rough on occasion. He is also not above scolding Hiro or becoming upset with him, getting angry at Hiro's unwillingness to try and make something of his life, showing a slightly frustrated side to his personality not seen anywhere else. He encourages Hiro to be the best that he can be and supports him in his endeavors. He was also sneaky, as he promised Hiro he would take him to a bot fight but in reality took him to his university, claiming he "needed to get something" before they headed off in order to get Hiro to come to his university and become interested in it while technically keeping his promise of "taking him to the bot fight" without actually doing it.

However, he was also shown to have a silly, goofy side to himself. When he introduced Baymax to Hiro and Baymax asked if he is experiencing any pain, Hiro asked "physical or emotional", causing Tadashi to comically pout. When Hiro ran out of ideas, he grabbed Hiro and shook him upside down in order to shake some ideas into his head and stated that Hiro needed to "look at things from a different angle"--a philosophy that Hiro eventually adopts as his own during the film. He was also excitable, as shown when he was happy after finally activating Baymax (after 84 tests) and ran around and kissed Baymax.

Tadashi also values his aunt; he does not like to make her upset and is appreciative for all she has done to raise them, especially having done it alone. His concerns extend to the general public, developing Baymax with the sincere hope that the healthcare companion would help people all over the world. He is dedicated to helping others no matter what the cost is to him--a statement undeniably proven when he makes the ultimate sacrifice in an attempt to protect his teacher.


One night, in the city's illegal underworld, Hiro engages himself in a bot fight against a group of thugs, specifically the boisterous Mr. Yama. After facing a humiliating defeat, Yama seeks revenge by ordering his goons to attack the young genius, who is immediately rescued by Tadashi on his scooter. The brothers make their escape as Tadashi reprimands Hiro for his actions, only to find themselves caught and arrested by the San Fransokyo police. Yama and his gang are forced to share a cramped cell with Tadashi, while Hiro has a separate cell to himself due to being a minor. Tadashi was not happy with this and silently glared at Hiro across from his cell for getting them into the situation. Fortunately, they are released on account of Aunt Cass, who scolds the two on the ride home.

Frustrated with Hiro's bot-fighting obsession, Tadashi takes his younger sibling to his school, the San Fransokyo Institute of Technology, in hopes of sending him down a better path. At the Institute, Hiro meets Tadashi's closest friends (Go Go Tomago, Wasabi, Honey Lemon and Fred). Tadashi then takes Hiro to his lab and shows him his latest invetion, the robot Baymax, and before leaving, they meet Professor Callaghan—an aspiring master of robotics and Hiro's personal idol. The experience successfully manipulates Hiro into having a strong desire to attend the school. To gain acceptance into San Fransokyo Tech, Tadashi suggests that Hiro participate in the school's annual science fair. Should his invention and presentation impress Callaghan, he'll be allowed enrollment.

Unfortunately, Hiro reaches a creative rut until Tadashi steps in and advises that he look from a different angle. Tadashi's advice leads to the creation of the Microbots. On the night of the fair, Callaghan shows amazement at the sight of Hiro's latest invention, leading to the latter's acceptance into the school. After the successful presentation, Tadashi and Hiro have some time alone, during which the older brother congratulates the younger one on his accomplishment, showing pride in the new path that he's willing to take. Just then, a fire breaks loose at the school and the brothers immediately rush to the action. While most civilians manage to escape, Tadashi learns from a survivor that Callaghan is still trapped inside the burning building. With no help around to save him, Tadashi volunteers his own life. A fearful Hiro immediately stops his brother, but reluctantly allows the decision upon seeing Tadashi's humanity and motivation to rescue his mentor. After rushing inside, the building violently explodes, killing Tadashi (even though his final moments are not shown, the junior novelization implies that he was crushed by a falling beam).

After Tadashi's death, the people of San Fransokyo mourn his loss while a heartbroken Hiro falls into a deep state of depression. Hiro, with the help of Baymax, eventually finds clues about a mystery man who might have been involved in Tadashi's "accidental" death, and forms a superhero team along with Tadashi's friends to avenge him. The quest leads them to find out that the fire at the SFIT was not accidental, but rather, an attempt by none other than Professor Callaghan to fake his own death and get revenge against Alistair Krei anonymously over an accident that involved Callaghan's daughter.

Callaghan was well aware about Tadashi's death, but coldly told Hiro that his death was his own fault for going inside to save him. Consumed by anger and frustration over this statement, thinking Tadashi's death was in vain, Hiro tried to force Baymax into killing Callaghan, but the man escaped and Baymax was reverted to his caring-self thanks to Hiro's friends.

Hiro took Baymax away to try and put the violent chip inside him again, but the robot instead showed him a series of footage which was recorded while Tadashi was in the process of building the healthcare companion to comfort the boy. In it, it is shown that Tadashi had spent multiple attempts testing and perfecting the robot, each time ending with a major failure. Although there were many major setbacks, Tadashi never gave up on building him. During the eighty-fourth test, Baymax was finally functional, causing Tadashi to express excitement for his hard-earned success. With Baymax working properly, Tadashi stated his eagerness to now be able to help others with Baymax, especially when he would get to show Baymax to Hiro. Tadashi's inspiring words and loving ways throughout the footage successfully heal Hiro's damaged heart, and as such, the young prodigy vowed to use his intellect for the better, which he does by defeating Callaghan and getting him arrested, rather than attempting to take his life again.

Tadashi then becomes a key character in "Baymax Returns"; after Callaghan's arrest and Baymax's demise when the robot saved Callaghan's daughter (who turned out to be trapped inside a mysterious wormhole), the recently formed superhero team disbands and Hiro is finally ready to attend the San Fransokyo Institute of Technology. Before his first day in class, Hiro watches a video on his phone about himself riding a bike, helped by Tadashi to do it all alone. Hiro pauses the video and looks at Tadashi woefully, then sets off to the Institute.

He is taken on a tour by his new friends, but the first thing he does is go inside Tadashi's former lab and wishes he was still there. He finds a notebook that contained Baymax's blueprints, and the hand of Baymax's armor, which was the last remaining thing from the robot. The hand though, contained Tadashi's healthcare chip and Hiro eagerly realized he could buy a new body for the robot, since the chip would still contain its memories. Hiro is interrupted by Professor Granville, who tells the boy that he must earn the lab before working on it, like Tadashi once did.

Yama also returns with a robot army of his own, so Hiro and his super-friends reunite once more to stop him, and after foiling his plan they officially become the superhero team known as Big Hero 6, deciding to help people in honor of Tadashi as it was his dream to do so.

During the film's credits, a newspaper reads about a ceremony of a building dedicated in Tadashi's name taking place, in which Hiro accepts the honor on behalf of his late brother. Krei Tech Industries builds the hall in the SFIT.

In "Failure Mode", Hiro feels like finally giving up after failing many times for his school project, but Baymax shows him the 58th test recording of his creation, where Tadashi himself also felt tired of so many failed attempts yet kept going nonetheless; Hiro never saw his brother like that, and the video motivated him to continue with his work.

In "Small Hiro One", Hiro gets Tadashi's copy of Dr. Trengrove's thesis, and gets it signed but Trengrove incorrectly signs it "To Kiro". Hiro also mentions that said thesis was the inspiration for Baymax's creation and that Tadashi admired Trengrove greatly.

Hiro goes back to bot-fights in "The Bot-Fighter", so he is arrested by the police again. Aunt Cass becomes upset for this and grounds Hiro. At his room, Baymax shows him a video where Tadashi says he doesn't know what to do to get Hiro out of bot fights, saying that he is a good kid who is wasting his talents. This helps Hiro into focusing on his mission, and after realizing that his new friend Trina was behind many bot thefts happening at the city, Hiro tries to convince her out of it by telling her how Tadashi had helped him before. Trina however refuses and escapes while leaving a bot to attack Hiro and Big Hero 6.

Trina then meets with her father, Obake, at a warehouse and shows him the video of Hiro mentioning Tadashi, which helps Obake in coming up with a new way to persuade Hiro into joining him. Obake then researches more about Tadashi, and during Halloween, secretly puts digital imaging lenses into Hiro and his friends' eyes. Hiro soon begins seeing Tadashi walking around places, beginning when Big Hero 6 face Noodle Burger Boy and the vision of Tadashi confused Hiro, allowing Noodle Burger Boy to escape.

When Hiro is at his garage fixing Baymax from another fight with Noodle Burger Boy, he sees Tadashi once again and asks Baymax if he sees him too, but Baymax responds that Tadashi is gone. Still, Hiro goes out to follow his brother and ends up in Mr. Ohare's House of Scares, the place where the lenses had been implanted into him. Tadashi then calmly begins a conversation with Hiro, asking how Aunt Cass is doing and what has happened since his death. Hiro happily talks with him, mentioning that he misses him, but soon Tadashi tells him that he shouldn't waste his talent on fixing Baymax. This makes Hiro realize that the Tadashi he has been following around and speaking to is not the real Tadashi and soon figures out that he has digital imaging lenses. Tadashi's cap then morphs into Obake's symbol, and with Obake's voice, Tadashi calls him a clever boy. Hiro then removes the contact lenses and sees that everything was just an illusion by Obake.

Later, Hiro reunites with his friends and gets sad due to how real it felt to be with his brother, then wonders how Obake could know so much about them. Then, Obake is seen at his lair watching a video of Tadashi's tests on Baymax.


Hiro Hamada

Hiro is Tadashi's younger brother and likely the most important person in Tadashi's life. He and Hiro had also become best friends, considering their duo as an 'exclusive club', according to the book Hiro and Tadashi. They liked to keep secrets and establish rules that only the two can know. They shared a bedroom presumably since they first moved in with Aunt Cass 10 years prior to the events of the film, allowing Tadashi to always be there when Hiro needed him, academically or emotionally. Because they were raised together, no one knew Hiro's emotions and issues better than Tadashi and vice versa. Tadashi was also the one who encouraged Hiro to become interested in robotics and they are seen assembling a robot toy together in a family photo as children. Hiro's health, happiness, and well-being were of utmost importance to Tadashi and he was disappointed when Hiro continued to bot-fight underground instead of trying to do something productive with his incredible intelligence. He not-so-subtly persuaded Hiro to apply at San Fransokyo Tech and pursue a career in robotics alongside him and is tremendously proud when Hiro succeeds.

Aunt Cass

Cass is Tadashi's over-worked but loving aunt. She had raised him and Hiro for a decade since their parents died, although she admits that she's not perfect. He hated making her upset and tried his best to make her proud, encouraging Hiro to do the same.

Go Go, Wasabi, Fred and Honey Lemon

Wasabi, Go Go, Honey Lemon and Fred were Tadashi's classmates and closest friends. They were shown to have a close bond and were regularly seen with one another outside of school. After Tadashi's death, the remaining group members took it upon themselves to watch over Hiro and eventually welcome him into their circle of friends. Not only that, but they also carried out Tadashi's hopes and dreams of helping the world by remaining members of the Big Hero 6 superhero team.


Tadashi is the creator of Baymax. Before completing him, Tadashi suffered from Baymax's unintentionally erratic and violent behavior, such as quickly jabbing into Tadashi's head with his fingers, shorting electrically (creating a burn hazard) or hurting his ears with high-pitched noises. As soon as Baymax functioned properly, however, Tadashi was ecstatic, humorously running around the room excitedly before asking the robot to scan him. Tadashi was incredibly hopeful at the existence of Baymax, hoping that someday, the healthcare companion could help the sick and injured all over the world.

After Tadashi's death, Baymax takes his place as Hiro's emotional support, something that Hiro doesn't initially want, nor does Baymax understand. Attempting to make sense of Tadashi's absence is also one of the first times that Baymax deviates from his normal functionality. At one point, he calls Tadashi's name while looking at Tadashi's belongings, wondering where he is and when he will come back, something unusual for him at this point. He did not understand that Tadashi could be dead, as he had previously scanned him and calculated that Tadashi was in excellent health at the time.

Professor Callaghan

Professor Callaghan was Tadashi's professor and mentor at the San Fransokyo Institute of Technology. The two shared a unique relationship amongst the institute's crowd, as they showed a high level of mutual respect, bordering the lines of a father/son relationship. On Tadashi's side, the young prodigy admired Callaghan greatly for his aspiring ways and innovations in the world of science and technology. Like his mentor, Tadashi was shown to be an inspiring and wise innovator, especially towards Hiro and his friends. Judging by their interactions and similar outlooks on science and intellect, it can be implied that Tadashi learned such traits from Callaghan.

The strength of Tadashi's admiration for Callaghan was truly established moments before the former's death, as the young man was tragically killed trying to save his mentor from a huge and deadly fire. Unfortunately, the sacrifice was ultimately for nothing, as Callaghan was the one responsible for starting the fire, which he did in order to cover the tracks of his crime of stealing Hiro's microbots. When Callaghan told Tadashi's little brother Hiro that Tadashi died on his account, Callaghan showed no remorse for causing the tragedy, callously dismissing Tadashi's death as his own mistake. With this, while Tadashi obviously admired Callaghan, it is unknown whether or not Callaghan truly cared about Tadashi. However, the very least that can be said is that Callaghan did not intend to outright kill Tadashi when he started the fire to cover his theft of the microbots.

According to the junior novelization, Callaghan was also the last person Tadashi saw before meeting his demise.


  • Tadashi - Tadashi is a Japanese masculine name. It has many meanings, but is known for meaning "righteous", "correct" or "true". Simply put, the name describes a good, honest person, fitting as Tadashi is loyal to his friends and family, and true to himself and to others. His name written in kanji is 浜田義 (Hamada Yoshi); the kanji 義 also means "morality", "duty", or "honor".


  • Tadashi's role is similar to Hiro's father in the comics, Tomeo Takachiho, whose death prompted Hiro to build Baymax to fill the void left in his heart.
  • Although his death was accidental, the 2013 Rotoscopers video and early information regarding the plot somewhat implies that Tadashi was deliberately murdered by Yokai in some early drafts of the script. The Rotoscopers video also depicted Tadashi as already attending classes with Hiro and was also the man in charge of a science research team (most likely consisting of Honey, Go Go, Wasabi and Fred) in which each individual would make different things and would eventually lead up to a competition.[4][5]
  • During an interview with Tadashi's voice actor, he said that Tadashi would be around 19 or 20 years old.[6]
    • According to Japanese media, Tadashi was said to be 21 years old[7], but this information is contradicted by official Disney publications, which state that he is 18.[8]
      • When Tadashi and Hiro are jailed for a short while, it is subtly confirmed that Tadashi is at least 18 because he's in the same cell as the other bot-fighters. Hiro is 14 and had a separate cell, so if Tadashi was a minor he'd have his own cell too.
  • Artwork by the film's character designer Shiyoon Kim suggests that Tadashi wore glasses at some point. In older concept art, he was also much older in appearance.
  • The colors of the logo in Tadashi's hat invert between the film and the illustrated books. In "Hiro and Tadashi", the N is red while the S and F are gold, but it is vice versa in the film.
  • In Avengers: Age of Ultron, when Tony Stark grabs the A.I. Card for F.R.I.D.A.Y., there is another A.I. called "T.A.D.A.S.H.I." on the table.
  • In the Korean dub he is renamed Teddy Armada.[9]
  • In the Japanese dub of the film and TV series, Hiro frequently refers to Tadashi as "nii-san", which means older brother in Japanese. His name is also pronounced "tada-shi" rather than "ta-DA-shi".



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Tadashi Hamada.


  1. Trengrove's thesis was revealed to be stolen work, but this was unknown until after Tadashi's death