Roxas
Roxas introduces the adventure as the central player character, passing his time in Twilight Town along with his friends. Though he might not look it at first, nor does he even realise it himself, he is not just another kid mourning the onset of school. His story is a little more complex than that.
Roxas was created from Sora during the events at the climax of Kingdom Hearts, as Sora briefly became a Heartless. Due to his unusual birth he has no recollection of ever being Sora, and as a result does not know why the Keyblade holds a special connection to himself and why the events of the world seem to revolve around him. And they quite literally do in his simulated Twilight Town, where he has been kept safe from Organization XIII until Sora is ready to reunite with him.
I did warn you that it was a bit tricky.
As the story opens Roxas' link with Sora is being strengthened, resulting in some very strange effects on his mind and even on the world around him. When the restoration is complete at the end of the chapter, they reform as one and Sora takes on the statistics and abilities gained by Roxas.
