One stormy night, a terrible darkness invaded the Destiny Islands, transporting Sora to another world far away from his friends. There, in Traverse Town, he met Donald and Goofy, who told him of a mysterious threat on many worlds. The three of them set off on a journey to find their missing king and Sora's friends. Their adventure led them to meet new people, overcome great ordeals, and finally to reunite with the ones they had been searching for.

But, in order for them to save the worlds, a special door would have to be locked, once again separating Sora, Donald, and Goofy from their friends. Once the door was closed, it was very likely they would never see each other again...

Sensing Sora's hesitation, the King said: "Don't worry. There will always be a door to the light." Thus the three heroes departed on yet another journey.
Time passes quickly...

In their search for the door to the light, Sora, Donald, and Goofy meet many new people and reunite with old friends. But theirs is a perilous path, fraught with enemies that attack them relentlessly. Heartless, Nobodies, and Organization XIII...

Each group has its own agenda. What will remain for Sora and his friends after they've all had their say?