Koei Tecmo recently filed a new trademark in the United States for a Yaiba: Ninja Gaiden Z, suggesting a possible new release to be announced in the near future.
Yaiba: Ninja Gaiden Z is a third-person hack and slash spin-off of the Ninja Gaiden series that was originally developed by Spark Unlimited and produced by Comcept’s Keiji Inafune in March 2014 for PS3, Xbox 360, and PC.
The trademark was filed on January 2, 2019 so we can expect some kind of announcement in the near future. Perhaps a port or remake could be announced for its fifth anniversary that is coming in a couple months.
Yaiba: Ninja Gaiden Z released on the PlayStation 3, Xbox 360, and PC.