From publisher blurb:
The Grand Stair stretches behind the scenes of the multiverse,
The Doors upon its unfathomably vast span leading the way to gossamer worlds of limitless variety and infinite possibility. The Tetsujin Shogunate used to be a normal-ish version of Earth... before little green men crash-landed in feudal Japan and started building giant robots. That, as you might expect, shook things up a bit.
Tetsujin Shogunate is a realm where gigantic samurai robots rise to do battle against monsters of epic proportions. Two alien races - the kappa and the oni - are stranded on Earth, and now use the remnants of humanity as pawns in their ongoing war. Shoguns, samurai, and ninja struggle on behalf of the human race - or perhaps vie only for their own survival - all in the shadow of clashing titans.
Gossamer Worlds: Tetsujin Shogunate presents one of the infinite possibilities within Lords of Gossamer and Shadow by Jason Durall, powered by Erick Wujcik's Diceless Roleplaying.