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

Crayon Shin-chan: Shrouded in Mystery! The Flowers of Tenkazu Academy

The film's story begins with Shinnosuke and his friends of "Kasukabe Defence Force" experiencing a one-week stay in "Tenkatouitsu 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 or 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.

(Source: Wikipedia)