Ninja Gaiden Sigma 2 is coming to PlayStation Vita in Japan (and the west presumably) in 2013.
The Vita version will be a straight up port and will integrate Vita’s unique control scheme into it’s gameplay. The original Sigma game was released earlier in the year as a Vita launch game.
Sigma 2 was released on PlayStation 3 all the way back in 2009. A new Ninja Gaiden game, NG Z, was already announced earlier today.
More on both these games as we get it.