User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170412001730/@comment-10330822-20170413074329

You don't really need to be Spanish to speak fluent Spanish though, he could be just fluent at it as a second language. Besides, he also apparently speaks Japanese, or English depending on the translation. XD I mean, isn't the assumption here that all of these beings are speaking Japanese by pure coincidence, like Namekians on Namek all speaking Japanese/English? The devils have "language" so they have an excuse, but no one really explains why Asia, Freed, and Xenovia all knew fluent Japanese, they weren't even supernatural. At least Irina is originally Japanese.

That's kind of the joke of anime where the characters are from different countries and yet speak fluent Japanese like they grew up there.

Say what you want about Infinite Stratos's German, but at least they acknowledged that these girls would have accents in the English dubbed, and didn't have them all speaking flawless English.

Plus, As far as we know Kiba was given the name Isaiah from the Church facility he grew up in, so it probably has nothing to do with his ethnicity.