在After making a heartfelt wish, elementary school students Itsuki (played by Kuroki Tsune), Taiichi, and Shinni encounter a mysterious old bookstore owner (portrayed by Kamiki Ryunosuke) and come into possession of a book titled "The Monster Encyclopedia." This chance meeting plunges them, along with their novice teacher Yoko Hayama (played by Aragaki Yui), into the perilous world of mythical creatures. Together, they must risk their lives to complete various tasks outlined in the encyclopedia, joining forces to capture an array of fantastical monsters.

As the adventure unfolds, secrets long hidden by the boys gradually come to light, while Ms. Hayama is forced to confront her own inner struggles. Will they succeed in completing their mission and seeing their wish fulfilled? This thrilling journey will take them—and the audience—beyond anything they could have imagined!