Wonderduck saw the the no-pants show:

Pants would make it difficult to get into the Striker Unit, and perhaps the Striker Unit needs direct contact with the witch to work.

I wish it made that much sense, but unfortunately for that theory, nobody in Yoshika's school wears pants either. Not even a mini-skirt. I prefer the explanation that creators do not have respect for their own story.

Then name most of the characters after WWII fighter pilots (Erika Hartmann, Sanya Litvak {who is NOT a trap, darnit!}, Charlotte Yeager, etc etc etc), and it just gets better and better.

I have created this idiotic meme in Steven's comments by observing that a) Miss Litvyak was the only female prototype, and b) Sanya is a shortening for Alexander/Alexandra not commonly applied to females. Now I just feel embarrassed blogging this. Not even Nekona made that observation. Speaking of which, Nekona made another: the series is too short to give every character screen time. Therefore, it's likely that we'll never know anything about Sanya's background, and so fans can continue to entertain their sick fantasies. Oh well, it's not much worse than "Gimly is a girl (and Legolas figures it out)".