For a long time, Final Fantasy games didn't get any sequels. Each release remained stand-alone, their stories encapsulated entirely by the cartridge or disc they came on.
In 2003, Square Enix broke off from this tradition and released Final Fantasy X-2, a direct sequel to Final Fantasy X. Next year they'll be doing it again with Final Fantasy XIII-2.
That's pretty much were the similarity ends, though. While X-2 eschewed the more somber atmosphere of X and instead went for a more poppish vibe, XIII-2 will reportedly do the opposite. Producer Yoshinori Kitase and director Motomu Toriyama made it clear in a feature on Dengeki Magazine that the story in XIII-2 will be a tad darker compared to the original.
This darker story will continue the events that transpired at the end of Final Fantasy XIII and complete the original's plot. It will have its own twists and turns and will not be so straightforward.
Central to Final Fantasy XIII-2's story will be the goddess Etro. While we don't quite know what her role will be, it will no doubt be tied to the main characters' quest to find a gate to an invisible world called Bunibelle.
Speaking of characters, Lighting and her friends from XIII will be returning of course, although some of them will undergo "major and unexpected changes". The XIII-2 team reportedly took in criticism from gamers regarding characters, the story, and the interface, so maybe some of those changes won't be so unexpected after all.
Square Enix have also paid special attention to the game's battle system, which Kitase and Toriyama say has evolved. They are also considering the inclusion of the Easy mode added to Final Fantasy XIII Ultimate Hits International.Final Fantasy XIII-2 is set for release in Japan sometime next year. A western release has been penciled in for next winter. To further whet your appetites for this sequel, here's the teaser trailer released a few days back.