While trawling for material about the Zeppelin name, to confirm my belief that Asuka, via her mother, is indeed the scion of Prussian nobility, I found that someone had already made some interesting discoveries, that a branch of the Zeppelin family had contacts with Japan in the early 19th century

http://www.evamade.org/forum_viewtopic.php?8.34478

Interesting stuff, though I might question whether Anno was aware for all this.

Before I saw this new information, I had been convinced that a red-haired, blue-eyed girl of Japanese and german decent was so great a statistical impossibilty, that it was likely no such human would have existed by 2015.