Settings and Areas
The world primarily consists of The City (中心街, Chūshin-gai?, lit. "City Centre"). The city can be explored at day or night though heartless are not present during the day. The city is fully explorable on the street levels and climbing vertically can be used to explore the top of buildings. Intertwined though the city are elevated streetways which can slid on using flowmotion. The unexplorable areas of the city are cut off using Hiro's AR Device that he gives Sora.
The city is comprised of three districts. The most iconic part of the city is the South District (南エリア, Minami Eria?, lit. "South Area"). The South district is composed mainly of many tall buildings huddled up together which contain neon lighting at night. The Honeydew Flan is located on a building on the east side of the region. Big Hero 6 team member Fred can be found on the long bridge above the large mechanical sushi-cook character. Talking to Fred will enable Sora to practice Hiro's orignal Flash Tracer course.
The Central District (中央エリア, Chūō Eria?, lit. "Central Area") has tall buildings like the south district though they are primarily on the east side and are more spaced out. Go Go Tomago is located on top of the large blue neon-striped building. Talking to her will enable Sora to partake in Hiro's 2nd Flash Tracer course. Directly east is a circle shaped building containing a battlegate at the very top. Honey Lemon can be talked to on a secondary region towards the middle of the building. The west side is comprised of smaller grey colored buildings. Prominently featured in this area are fish-shaped wind socks overlooking the city which can be accessed through air-step.
The North District (北エリア, Kita Eria?, lit. "North Area") is the smallest district of the three. This area has two taller buildings overlooking it and smaller-apartment like structures on the west side. Wasabi can be found on one of the buildings within the apartment region, closest to the railways. A battlegate is located at the end of the accessway of the railroad on the east side. Sliding on the railways will take the party through a tunnel leading back to the south district.
Hiro's Garage (ガラージ, Garāji?, lit. "Garage") is a small resting area that can be accessed through two city exit points on the west side of the central district and through the southwest side of the south district.
The Bridge (橋, Hashi?) can only be accessed during the world's initial opening battle or through the battlegate in the North District.
Upon Sora, Donald, and Goofy's arrival, Sora is already impressed with the metropolitan feel the world gives out. The moment is ruined, however, when Heartless attack and send a girl flying. Hiro and Baymax then fly in to check in on Go Go where the trio introduces themselves to Hiro and Baymax. The team clears out the Heartless on the bridge and they return to Hiro's Garage.
Hiro introduces Wasabi, Go Go, Honey Lemon and Fred of Big Hero 6 while Sora introduces themselves as Keyblade Hero 3, much to the confusion of Donald and Goofy. Sora tells the team about the Heartless threat and say that they can take care of the problem, but Hiro has an idea on how to help. He gives Sora an AR Device and Sora uses it to do a Flash Tracer circuit around the city with Big Hero 6. The training is a success with Big Hero 6 modifying their gear, thanks to Sora's inspiration. When the Heartless invade the city, both the newly dubbed Keyblade Hero 3 and Big Hero 6 easily take out the Heartless and Baymax teaches Sora how to fist bump to celebrate the victory.
While the whole group rests to eat ice cream at the bridge, Hiro tells Sora about his deceased brother Tadashi. Hiro says he is still alive, in a way, because of how much he has inspired and influenced them.
At night, the city is attacked by Darkubes. Hiro assumes they are his Microbots. Hiro returns to his garage in order to see if there are any leads as to who is controlling them. Upon examining, the Darkubes he confirms they are not his Microbots and begins to incapacitate Go Go, Honey Lemon, Fred, and Wasabi in the city, prompting in Sora, Donald, Goofy, and Baymax to rescue the members. Upon heading towards the rooftop, Sora encounters Dark Riku a member of the real Organization XIII, who is observing the data stored on from the combat chip as an experiment on recreating a heart from data. During a fight with the Darkubes on a roof, Hiro returns and meets Dark Riku, who refuses to return Baymax's chip to Hiro.
The next day, everyone finds Dark Baymax with Dark Riku. Once Dark Baymax is defeated, Hiro contemplates destroying Dark Baymax's infected chip, although he uses his resources to save the original Baymax.
Sometime after Xehanort's defeat, Big Hero 6 strike a pose after saving a bridge from collapsing, as well as preventing two cars from falling off the edge.
While in San Fransokyo, Sora wears an AR Device given to him by Hiro.