Crayon Shin-chan: Mystery Meki! Hana no Tenkasu Gakuen

The film's story begins with Shinnosuke and his friends of "Kasukabe Defence Force" experiencing a one-week stay in "Tenkatōitsu Kasukabe Private Academy" (nicknamed "Tenkazu"), an elite boarding school that is administrated by a state-of-the-art AI, "Otsmun". All the students are given a badge initially with 1000 points and their points are increased/decreased by Otsmun based on their behaviors and academic performance.

In there someone attacks Kazama.

As a result, his intelligence is reduced, and strange bite marks are left on his butt.

The Kasukabe Defense Force joins forces with the school's dropout student council president Chishio Atsuki, who was a former athlete, to form a group of detectives and solve the mystery.