Is Square Enix Developing A Game About The Underworld?

We ask this question because the publisher filed two trademarks in Japan with "underworld" in them. The first, roughly translated, is Door of the Underworld and the Path of Nayuta and the other is Root of the Underworld.

Interesting. Square Enix already made a game where Hell is the setting, remember Army Corps of Hell? I wonder what these could be for, perhaps these are tied to the unnamed game with the medieval looking fellow in it?