It reminds me now of what I think is called a "Forward" (correct me if I'm wrong). Anne and Todd Mccaffrey used this at the beginning of most of the Dragonriders of Pern novels to explain the world of Pern to newcomers as well as set the framework for the narrative.
To summarize a text equivalent of what an outsider might think:
"In the beginning there were 3 nations who battled an evil empire that dropped a Dragon-Ball on their continent. Many were killed. In a last ditch effort, Mr. Oldguy, with the help of blonde Heart Throb, Midget & Blind Girl, and Kitty Mage, attempted to reseal the dragon in another ball, but it broke (probably because you have to weaken the Pokemon first). Mr. Oldguy then sends the warriors of the three nations forward in time.
These warriors find themselves in a place that is still beautiful, but there are still dangers among the shadowy trees and icy mountains. Fortunately Heart Throb, Midget, Blind Girl, and Kitty Mage are all there, and these warriors are ready to face this new world head-on."
Seems like a good enough introduction to me.