How'd the european house come to rule over the extremely nationalistic Japan? The country out and out closed its borders to foreign influence for the longest time and has shades of extreme nationalism and recalcitrantly sticking to their own traditions even nowadays, it's part of their whole culture.

Being inspired by anime doesn't really mean it has to be set in Japan, especially if the entire thing is going to revolve around europeans and european terminology, it'd make more sense for it to be set somewhere in nondescript Europe or for the houses and terms to be Japanese-inspired as well.