Crayon Shin-chan: Fast Asleep! The Great Assault on the Dreaming World!

The Nohara Family and the Kasukabe Defense Forces team up to address a nightmare infestation in the dream world. After a bizarre dream where residents are swallowed by a giant fish, people in Kasukabe start having control over their dreams, but things quickly take a turn for the worse as the dream world transforms into a nightmare. Saki Nubatama joins the group, and they investigate the cause of the change, venturing into the dream world.