A genius with a natural talent for science. After his microbots were recognized, he was recommended for early admission to university at age 14. He is emotionally expressive, highly knowledgeable about science, and full of curiosity. Gender: Male. Appearance: Black, slightly messy hair, brown eyes, and a slender build. He usually wears T-shirts or hoodies. Nationality: Japanese-American. Field of expertise: Robotics engineering.

Hiro's older brother and the creator of Baymax. He built Baymax at the San Fransokyo Institute of Technology. He is wise, cheerful, and compassionate toward everyone. Age: 20. Appearance: Short black hair. He is rarely seen without his favorite red baseball cap. Nationality: Japanese-American. Field of expertise: Robotics engineering major. Gender: Male.

A kind-hearted healthcare companion robot created by Hiro's brother, Tadashi. He can speak clearly like a human. Appearance: A white, inflatable vinyl body that makes you want to hug him. He is programmed with 10,000 different medical procedures. His "heart" is a medical chip stored in a port on the left side of his chest. He is gentle and has zero combat ability, but he will risk his life to protect everyone in a crisis. Personality: Unknown (Robot).

Tadashi's classmate at the San Fransokyo Institute of Technology. His name comes from a nickname Fred gave him after he spilled wasabi on his shirt. Nationality: Black. He is a neat freak who keeps all the equipment at the lab perfectly organized. Meticulous, timid, and prone to worrying. He is a logical thinker. Appearance: Large and muscular with dreadlocks. He prefers green clothing. Field of expertise: Laser technology and plasma physics. Gender: Male.

A student at the San Fransokyo Institute of Technology specializing in electromagnetic suspension. She is cool, quiet, and blunt, but deeply cares for her friends and has incredible athletic reflexes. She is almost always seen chewing gum. Appearance: A slender, fair-skinned woman with black hair. Nationality: American. Field of expertise: Mechanical engineering.

A student at the San Fransokyo Institute of Technology and an expert in chemistry. She has a happy and optimistic personality. She is tall and wears large, round glasses. Appearance: Often wears lemon-yellow trench coats or long jackets and has long hair. Field of expertise: Chemistry. Nationality: White. Gender: Female.

The mascot of the San Fransokyo Institute of Technology. He is easygoing and cheerful. A massive fan of monster movies, he lives in a mansion and has a huge collection of action figures. While he seems like a carefree eccentric, he has a mysterious side. Appearance: A slender white male. Nationality: American.