Fun concept, but maybe not really suitable for a wall, seeing the large empty space on the right. On the other hand, if people got lots of icons on their desk, that's the place to put it.
Anyway I think you did a nice job here, I really appreciate the original concept.

I like that you really tried to make this look like an old poster, which is cool, and were conscious of the need for icons [I'll assume that's why the right side is empty, and not because you were lazy]. However, I think that her armband looks weird because when you flipped her, the kana were all reversed, so it's the equivalent of backward letters. I think it would look better if you can get them back to their original state.

This anime made me laugh so hard that I had to have this wallpaper when I saw it...well done.