The ‘Rail World’ consists of 4 different regions, and four natural energies from the each region - Water, Light, Wind and Fire energy – are the forces that make the world go around, which circulate and interact with each other. In this Rail World, trains and Railers live together in harmony through the power of four natural energies, and also with the teamwork of the Rail Watch members protecting the Rail World safe.

There is an over-arching plot detailing the rivalry between the Goh-Rong Restaurant and the Sooga Island location of a multi-national restaurant chain called Dong King Restaurant. Ring Ring, a local 12-year old fashion star, who appeared in the Jetix show and also appeared as Pucca's rival for Garu's affections, is revealed to be the daughter of Dong King and at times works for him, while also directing his servants against Pucca. These servants, under the command of the Dong King Restaurant's manager, Fyah, continually attempt to steal the Goh-Rong's customers by means of various dirty tricks, including occasionally hiring villains such as Tobe and his ninjas or The Pirates.