Valkyria Revolution, despite its name and approximately similar art style, isn’t really a sequel to 2008’s incredible Valkyria Chronicles (or its slightly less incredible PSP sequels). In tone and gameplay, the differences between the two series are night and day, and Revolution looks considerably poorer for the comparison.
The new game, like its predecessors, takes place on the continent of "Europa"—shaped just like real-world Europe, but divided into fictional fantasy countries like Jutland and the Ruzi Empire. If you don’t recognize those two nations from Chronicles, that’s because Revolution takes place in an entirely new continuity.
That the sister series just happens to have nearly identical settings—as well as reuse terms like Valkyria and “ragnite”—is confusing and poorly justified. Taking control for the first time and meeting the game’s gang of barely introduced misfits didn’t do much to clear up why Valkyria Revolution needs to share so much DNA with its “predecessor.” My best, most cynical guess is that Valkyria Revolution was made to siphon off some of Chronicles’ cult status—not to mention the attention of fans still fiending for a true follow-up.