Mecha vs. Kaiju is a Fate Core system RPG book that’s up on Kickstarter now and looking for funding.
From the campaign:
Mecha vs Kaiju is a FateCore role playing game inspired by Japanese kaiju eiga (monster movies) like Godzilla and Gamera, and anime robots like Gundam and Evangelion. You take the role of a dashing pilot of the Mecha Assault Force, defending Japan against the depredations of the monstrous kaiju. But there is much more to the MvK setting than just slugfest setpieces. Your characters will embroil themselves in a conflict as old as time, against shadowy ninjas, hulking ogres, and immortal oni demons.