Nobita and his friends get transported to an animal planet after a mysterious pink fog appears inside his house. They work together with the natives to find the origin of the fog.

Lopple and Chammy, two runaway aliens, recruit Doraemon and Nobita to help save their planet from destruction.

As Nobita, Shizuka, Gian, and Suneo are auditioning for a role in their school's play based on "Journey to the West", the coveted role of Son Goku is hotly contested. After suggesting that the real Great Sage Equal to Heaven should play himself, knowing that the story is only a legend, Nobita and Doraemon go back in time to find their own fake Monkey King, but arrive in present day with the story's demons having taken over the world. The only way for things to go back to normal is for Nobita and pals to reenact the tale...for real!

Nobita, after wondering if Heaven truly exists, asks for Doraemon to take him there. When his robot pal suggests that they make their own Heaven, Nobita enlists Shizuka, Gian, and Suneo to help, but a war breaks out between two islands in the clouds that could have terrible environmental consequences if Nobita and Doraemon don't bring peace in time!