Doraemon Movie 02: Nobita no Uchuu Kaitakushi

Nobita is troubled by recurring dreams of a boy named Roppel and his companion Chami fleeing through space. The dreams become reality when a malfunction aboard Roppel's spacecraft creates a strange connection between the ship and Nobita's room, giving Nobita and Doraemon a doorway to a distant world.

On Roppel's planet, the two friends discover wide open lands unlike anything at home and quickly befriend the local settlers. Their excitement turns serious when they learn that powerful outsiders are forcing the inhabitants from their land for its resources. Nobita and Doraemon promise to stand with Roppel, turning an accidental path through space into a fight to protect his home.