Gainjinworks and Monkey Paw tease new Vita/PSP RPG

What could it be from the vast Japanese RPG archives? Gaijinworks has a teaser site (if you consider a single question mark a tease) up with a new RPG being promised for the PSP and Vita, They recently dragged Class of Heroes 2 kicking our way, and there's various thoughts bouncing around the net.

UPDATE: The site now has two PSP covers bedecked with question marks, suggesting a new series could be on the way.