The movie's plot involves Nobita, who throws a temper tantrum because he wants a really large RC toy robot in order to upstage the rich kid, Suneo Honekawa, who has been showing off the new robot that his cousin made. His fit makes Doraemon angry and he uses his Anywhere Door to get away from the summer heat, to the North Pole. Sometime later, Nobita follows and discovers a strange bowling ball-like orb which starts blinking with a pulsating light, and summons what looks like a giant robot´s foot. After Nobita uses the foot to sled down, crashing into his room through the Anywhere Door, the bowling ball follows him home through the door and another robot piece falls into his backyard. A frozen Doraemon follows soon after, covered in ice before being thawed out and with a cold. Learning of the robot parts, Doraemon admits to Nobita that he has nothing to do with it, and the two use the Opposite World Entrance Oil and the Roll-Up Fishing Hole to enter the World Inside the Mirror, an alternate mirror world without people. There, they build the robot which Nobita christens "Zanda Claus" as he believed the sphere summoning the parts is from Santa Claus.