A new game in the series was announced back at E3, but like so many others, only casually with no formal details. Spike and Acquire have now given the Japanese version a formal name, Shinobido 2: Sange, which is French for monkey, but I doubt that's relevant.
The new trailer looks very detailed and Famitsu has some new pics and a little info which translates, rather poetically to:
The open world full of color is unique to Japan, with PlayStation Vita by utilizing the power of expression, rich emotion has been drawn up to elegant suspicious. The darkness that was beautifully expressed with unique stealth ninja action, with blossoms of blood on arms sometimes go to various missions.