The VS series is in the era known as the Heisei Period wherein, when not only did Godzilla return after more than a decade's absence, but marked a transition between the reign of the Showa Emperor Hirohito to that of his son Akihito, now dubbed the Heisei Emperor.
The following films showed mankind's efforts to defeat Godzilla while also being challenged by other monsters such as Mothra, Rodan, and SpaceGodzilla. This series featured a specialized organization of monster-combating soldiers and engineers called G-Force. Several of the ways ways G-Force planned to stop Godzilla included the construction of two "mecha-kaiju", MechaGodzilla (who would do battle with both Godzilla and Rodan) and M.O.G.U.E.R.A, also called Moguera (vs. SpaceGodzilla).
History of Godzilla