Following the San Francisco earthquake of 1906 (retconned as the Great Catastrophe of 1906 in Big Hero 6: The Series), in which scientist Lenore Shimamoto caused the disaster when she attempted to invent a new form of unlimited energy that backfired, Japanese immigrants helped rebuild by contributing key Japanese building techniques that allowed the city to flourish and prevail in the face of the seismic events like never before. Following this restitution, San Francisco was renamed San Fransokyo in honor and recognition of it being a city reborn thanks to a combination of Japanese and American architecture, landscaping and engineering skills. The city's iconic amalgamation of American and Japanese culture followed soon thereafter.
The city of San Fransokyo is an Eastern-Western blend of aesthetics covering a fairly extensive region on the coast of the Pacific Ocean. It is host to such notable locations as the popular Lucky Cat Café, the mysterious Akuma Island and the illustrious San Fransokyo Institute of Technology. Downtown San Fransokyo is where the large majority of the events chronicled in the film take place. Japanese flora and fauna can also be found across the city, such as Japanese cherry blossoms and Japanese bobtail cats.
- San Fransokyo Institute of Technology: An esteemed university for gifted intellectuals and prodigies, it is the pride of the city's scientific and technological advancements.
- San Fransokyo Police Department: The police department is the prominent lawforce in San Fransokyo.
- San Fransokyo Art Institute: Another institution for talented artists and the rival of the San Fransokyo Institute of Technology.
- Frederickson Mansion: The residence of Fred's family and one of Big Hero 6's bases.
- Krei Tech Industries: A famous technology company owned by the infamous tycoon Alistair Krei.
- Downtown: The heart of San Fransokyo is found in the metropolitan center of the city, or "downtown". Several key locations are found here:
- Lucky Cat Café: A popular bakery, breakfast, lunch and dinner shop that doubles as the Hamada family home.
- Warehouses: Multiple warehouses can be found throughout the city and are used as hideouts for villains.
- Good Luck Alley: A district that is known for being the home of criminals, such as Mr. Yama and his men. It is named after the likely chances of people getting out of the alleyway, alive. The Food Fight competition is also held here.
- Go Go Tomago's Neighborhood: This dangerous place is home of thieves like Dibs. Go Go and Honey Lemon live in an apartment from this neighborhood.
- Shimamoto Boulevard: A place likely named after artist Lenore Shimamoto.
- Night Market Square: In this place there is a building known as Telegraph Tower.
- Richardson Mole's Comic Book Shop: Fred's rival works here, and has a secret base with videogames that antagonize Fred.
- SecuriTech: Building of a company that produces security devices and technology.
- San Fransokyo Trust: The city's bank.
- Cinema: San Fransokyo's movie theater.
- Noodle Burger Restaurants: A fast food chain with many restaurants all over town.
- San Fransokyo Museum of Art: A museum found in front of a Noodle Burger restaurant, which contains many artistic pieces and items.
- Akuma Island: An island off the coast of San Fransokyo Bay; the former test facility of Silent Sparrow.
- Muirahara Woods: A National Park found in the outskirts of town.
- Obake's Lair: Off the coast of San Fransokyo.
- Several real-life landmarks from San Francisco can be spotted in the city:
- Ghirardelli Square
- Golden Gate Bridge
- Transamerica Pyramid
- Port of San Francisco
- Coit Tower
- The city's newspaper is the San Fransokyo Tribune.
- The city has various easter eggs referencing other Disney animated films. These include, but not limited to: