The full title of Keiji Inafune's upcoming zombie game is Yaiba: Ninja Gaiden Z, the Mega Man and Dead Rising developer confirmed at a pre-Tokyo Game Show 2012 event this week (via Joystiq). While we had already heard about Inafune's plans for a new zombie game, the TGS reveal confirms that it's actually a spin-off of the Ninja Gaiden series.
The game will be developed as a collaborative effort between Team Ninja, Inafune's own Comcept, and Western studio Spark Unlimited, with Tecmo Koei publishing. Little more was revealed, though it's confirmed that the story follows a ninja named Yaiba as he slices through zombie hordes with the ultimate goal of taking down Ryu Hayabusa. Yaiba: Ninja Gaiden Z is currently in development for unspecified consoles.