User blog comment:LastationLover5000/Fairy Tail 371 - In Which Hiro Should Just Quit Out of Shame (Tartaros Arc: Part 2 - Song of the Heavenly Dragon)/@comment-25316424-20140214223453/@comment-4666155-20140214223759

That's actually my general theory. I don't even think Mira is actually human anymore, but is either full or half-demon, due to the nature of the Take-Over magic. For all I know, it's changed the composition of her body