Set 17 years after Final Fantasy IV, The After Years follows the original cast and their descendants in episodic tales as a new villain appears, setting into action a mysterious chain of events that threatens the fate of the Blue Planet. Largely utilizing assets, locations, and mechanics from its predecessor, the title nevertheless incorporates higher quality character graphics and several new gameplay systems.
Source: Wikipedia, "Final Fantasy IV: The After Years," available under the CC-BY-SA License.