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Not really, I believe I chose Riku, and my brother chose Sora. Everything still happens the same way it's meant to, just in a different order.  Timelinesplitter Chaos 12:33, December 28, 2012 (UTC)

No, it doesn`t matter who visits the world first, whether it be Sora or Riku. However, the game`s storyline indicates that, whoever you play, Sora is the first to enter each world, with Riku following in Sora`s path, though from what Joshua Kiryu said, each in  heir own dreaming of the world.