Well, I always have suspected that Akako's lineage had passed at least one gaijin in the past... Given Akako's age, her magic should be transmitted by blood (CCS and any other series-wise), and magic of such type is definitely European... Don't know about the Mary Ann joke, but I won't be surprised if "Koizumi Akako" is just a psuedonym. Kids with western-sounded names are definitively discriminated against in Japan.

Samuel Curtis, Shinichian and Hirokian.