Denja is a wanted criminal in 22nd century for bank robbery. During escape, he gets into an accident and has to be hospitalized at the same hospital that Doraemon went for checkup. With a help of Substitution Rope that is (conveniently) stuck out of Doraemon's pocket, Denja is able to swap his body with Doraemon's and escape the Time Police's detection as the Police chase after Doraemon in Denja's body instead.