We've just received word from Tecmo that Ninja Gaiden Sigma 2's demo will be gracing the US PSN one week after Japan gets it on September 24. Unfortunately, Tecmo wouldn't offer anything on what the demo would entail; the company did not confirm any co-op for the demo, let alone which part of the game it would take place in. But hey, it's a free demo and we certainly aren't complaining -- mostly because we don't want to be on that Ryu cat's bad side.