A back-story is a literary device[?] often employed in order to lend a story depth or verisimilitude. Characters or events related to a story may only be given cursory treatment so as not to distract from the central plot development.
Probably the most extensive back-story ever created was that created by J. R. R. Tolkien for his Middle-earth stories.
... in Japan and Europe but not in the United States.
However, because the GBA has no region lockout, European games will work fine on a U.S. GBA unit, and apparently, ...