The actual owner of Zanda Claus, Riruru seeks out Nobita when he accidentally lets slip all that he knows about the robot. However, Nobita forgot about the sphere that has been sending telepathic messages to a mysterious girl named Riruru. The group realizes just how dangerous Zanda Claus really is, and they decide to return to the real world and forget about ever having found the robot. The trio enjoy this but later, however, Shizuka accidentally presses a button on the control panel that makes the robot fire a huge laser beam that destroys a whole skyscraper. Using a brain wave controller that Doraemon pulls out of his pocket, Nobita has the robot perform gymnastic maneuvers in a mirror world before bringing Shizuka Minamoto to join the fun. There, they built the robot which Nobita christens the name "Zanda Cross" as he believed the sphere summoning the parts is from Santa Clause.
Learning of the robot parts, Doraemon admits to Nobita that he has nothing to do with it as 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. A frozen Doraemon follows soon after, covered in ice before being thawed out and with a cold.
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. Sometime later, Nobita follows and a discovers a strange bowling ball-like orb which starts blinking with a pulsating light, and summons what looks like a giant robot's foot. His fit makes Doraemon angry and he uses his Anywhere Door to get anyway from the summer heat cool off at the North Pole. 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, who has been showing off the new robot that his cousin made. ( October 2019) ( Learn how and when to remove this template message) Please help improve it by removing unnecessary details and making it more concise. This article's plot summary may be too long or excessively detailed.