Tadashi Hamada is the older brother of Hiro Hamada and a major character 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, the robotic Personal Healthcare Companion. Tadashi's sudden death in a mysterious fire catalyzes the events of Big Hero 6, leading Hiro, Baymax and Tadashi's friends to band together to investigate the "accident" and catch the person responsible for it.
Tadashi is a tall, slender, slightly muscular young adult male, of a larger build than others in his family. He is of mixed Japanese and Caucasian descent, which shows in his various facial features. He has large, warm brown eyes and neat black hair, cut above his prominent ears. His face shape is different from his aunt and brothers', 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 never seen without this cap in the film, except when he takes off his moped helmet, though it is also off in many family photos that can be seen. Since his 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. In the first day of the film—the day he introduces Hiro to his friends—he is wearing a white crew neck t-shirt with artwork of a ninja, 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 Tech 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, where Hiro retrieves and keeps it.
- (To Hiro) "You better make this up to Aunt Cass before she eats everything in the café."
- (To Hiro) "I hope you've learned your lesson, bonehead."
- (To Hiro) "When are you going to start doing something with that big brain of yours?"
- (To Hiro) "Unbelievable. Ah, what would Mom and Dad say?"
- "Fred's the one who comes up with the nicknames."
- "Wow. That is both disgusting and awesome."
- (To Hiro) "Shake things up! Use that big brain of yours to think your way out. Look for a new angle."
- (To Hiro) "I was just going to tell you your fly was down for the whole show."
- (To Hiro about Bot Fighting) "You graduated high school when you were thirteen, and this is what you're doing?"
- (To Hiro) "Welcome to nerd school, nerd."
- "Callaghan's in there, someone has to help." (last words to Hiro)
- (To Baymax) "You are going to help so many people, buddy. So many. That's all for now. I am satisfied with my care."