User blog comment:Seieireppa/God Eater ∂: Those Who Change History, chapter 4/@comment-14812118-20150422215054/@comment-1419424-20150422215839

It's basically actual Japanese history (if you know the story behind Oda Nobunaga) with two twists — one of these is the existence of the Aragami (and everything that came as a result), and the other, well... you'll have to wait and find out ;)