Shin-chan must rescue the adults of Kasukabe when they mysteriously abandon their responsibilities to relive their youth at the new 20th-century expo.
Shin-chan is approached by his time-traveling future bride-to-be Tamiko, who asks him to help save his adult self from the ruler of Neo Tokio.
Everyone's favorite TV superhero Action Mask shows up in Kasukabe, and he's trying to get something from Shin-chan -- but what could it be?
