A malevolent nightmare prompts the Kasukabe Defense Forces to join forces with the Nohara Family in a surreal realm. The locals of Kasukabe are plagued with strange dreams of a colossal fish devouring them whole, but they soon discover that they can manifest their most audacious fantasies during slumber. However, their elation is short-lived as the dreamland transforms into a perilous realm. To unravel the disturbing conundrum and explore this nightmarish realm, Shinnosuke Nohara and his comrades enlist the help of Saki Nubatama, a newcomer to the town.