Nobita, hearing Shizuka's wish to climb trees and play baseball, suggests, "Well, let's try switching bodies for a while!" He borrows a "Switching Rope" from Doraemon, which allows them to switch bodies while keeping their minds the same. The two immediately switch bodies. Shizuka, now in Nobita's form, is overjoyed to enjoy tree climbing, something she had always wanted, and to do well in baseball. She says she wants to stay like this for a while. Meanwhile, Nobita is constantly being scolded by Shizuka's mother for "misbehaving badly"...!?

Nobita wants to buy a manga book and asks for an advance on his allowance, but his mom firmly refuses. Unable to give up, he tries to secretly get the money early, but gets scolded and becomes discouraged. Frustrated, he decides, “If that’s how it is, I’ll just become a total villain!” and takes the “Devil’s Passport” from Doraemon. It is a terrifying passport that allows him to get away with any wrongdoing. Freed from being scolded, Nobita begins doing only bad things (like kicking empty cans and trash bags) taking advantage of the fact that no one can punish him.

Even though it’s his birthday, Nobita feels disappointed because he worries his parents’ present will once again not match what he wanted. Trying to distract himself, he visits Shizuka’s house, but while waiting for her to return, he becomes impatient and asks Doraemon for a way to skip wasted time. Doraemon then introduces the “Time Warp Reel,” a gadget that allows them to jump forward in time, leading Nobita to experiment with fast-forwarding to the moment Shizuka comes home.