What I would hope happens is that it's a new story in a new neighborhood, completely new characters (except Hanekoma and maybe Joshua due to their significance), but still the same universe and concept. I don't think we need to revisit the Shibuya story anymore.
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The Temple of Kraden, a forum for fans of Golden Sun:
http://z9.invisionfree.com/The_Temple_of_Kraden/index.php?act=site