Shin-chan's ass literally saves the world, and the movie commits to this premise with zero embarrassment. The gag is dumb, the execution is relentless, and somehow it works because the film understands that comedy this committed doesn't need permission to be ridiculous. If you're watching a Crayon Shin-chan movie expecting restraint, you're already lost.

Shin-chan and his crew are back for another ridiculous adventure that somehow manages to be both absurd and heartfelt in typical Shin-chan fashion. During a Nohara family vacation in Okinawa, an odd saucer-shaped object lodges itself on the rear end of their dog Shiro. It turns out to be a bomb dropped by butt-themed aliens, powerful enough to wipe out the planet. The space monitoring agency UNTI moves in to retrieve it, while a female terrorist band called the Hinageshi Opera Company interferes in hopes of grabbing the bomb for itself. The fifteenth film in the franchise pairs bomb-scare slapstick with a warm story about the bond between the Noharas and Shiro, and it adds musical numbers along the way. The film leans into the series' ecchi sensibilities while keeping its irreverent comedy.