A tiny rabbit from another dimension crashes through your floor at 3 AM and suddenly your bedroom is the least weird place in the story. Doraemon and Nobita tumble into a spaceship adventure that runs on pure setup-and-payoff comedy, the kind where stealing from the fridge matters as much as saving a universe. This is Doraemon at its coziest, a movie that treats impossible things like they're as normal as homework you forgot to do.

While Nobita is asleep, he suddenly feels the floor of his room shaking as if an earthquake were coming. Chamii, a small rabbit from an alternate universe, uses a hammer to open a door between dimensions and climbs into his room through the floor. Doraemon hears someone taking food from the kitchen fridge, and he and Nobita catch her in the act. Chamii then shows them the passage under Nobita's floor that leads into a spaceship. From the ship they see the Koya Koya Planet, and they meet a boy named Roppuru. The film mixes adventure, comedy and fantasy.