Professor Hiiragi and Count Collection, two mad scientists, collaborate to create a portal to the mythical alternative world of Sixgate. In a synchronized effort, they attempt to retrieve six powerful objects that nullify boundaries between dimensions. To prevent Count Collection from attaining the objects, Professor Hiiragi enlists his daughter Rokuna and her friend Mondo to become the Mon Colle Knights. Their mission is to integrate the magical Sixgate world with the human realm and establish dominance over all monsters, or even reset reality if necessary. It is worth mentioning that the information provided pertains to both the original Japanese version of the story and the Jetix adaptation.