When the Nohara family and the Kasukabe Defense Forces, led by Shinnosuke Nohara and his friends Kazama-kun, Nene-chan, Masao-kun, and Bo-chan, along with other Kasukabe City residents, find themselves trapped in a Wild West film world governed by the malevolent Justice, they must race against time. In this stagnant world, memories fade as the film remains incomplete. To return to reality, the group must vanquish Governor Justice and complete the film, preserving their recollections before they vanish entirely.