While Nobita is sleeping, he suddenly feels the floor is trembling, like there would be an earthquake in his room. A little rabbit from an alternate universe named Chamii opens the door between the dimensions using a hammer and gets
Doraemon: Nobita's Great Battle of the Mermaid King
Doraemon: Nobita's New Dinosaur
Doraemon: Nobita and the Island of Miracles – Animal Adventure
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