Like all of the games in the Tales of the World series, the game features crossover appearances of characters from other games in the main series. However, the game features an original story, featured in a new land named "Revaila" and two new characters, named "Terun" and "Nahato". Source: Wikipedia, "http://en.wikipedia.org/wiki/Tales_of_the_World:_Tactics_Union," available under the CC-BY-SA License.