You're watching a five-year-old's brain operate at full throttle without a filter. Shin-chan doesn't do clever, he does instinct, chaos, and the kind of comedy that hits because it's honest in the dumbest possible way. The mystery setup is just an excuse to watch him destroy every serious moment with obscene non-sequiturs and physical comedy that lands harder the less sense it makes. This is peak Shin-chan energy: nobody's learning anything, nothing's being subverted, it just works because a kid saying the worst thing at the worst time is always funnier than whatever the adults planned.
Crayon Shin-chan: Nazo Meki! Hana no Tenkasu Gakuen is a 2021 comedy movie from Shin-Ei Animation.