User blog comment:Hfc2x/HUMANITY'S WORST NIGHTMARE/@comment-12642484-20131126224322/@comment-179280-20131127092806

Well, in the panel that Nanaba dies (aka Nanaba split), you can see that she has boobs. We also know that in japanese, Nanaba uses feminine/formal watashi in both the anime and the manga, and in the anime, she has a female VA... so I guess that's the evidence we have in that regard. (And no, I'm not taking into account that annoying debate over referring to someone by their biological sex is gross and whatnot.)