This girl is supposed to be the stage 5 midboss of Mystic Square. Ayana is the name the fans gave her since she has no official name. Check http://en.touhouwiki.net/wiki/Ayana
I see no reason to not tag them. Sure, we could use extra and touhou to try and find images of a specific nameless midboss, but if we can directly label the character it shortens the search. Additionally by giving them a tag we are indirectly giving an incentive to search for and upload images of such obscure nameless characters and artists will begin to draw them more often as a result of people looking them up, liking them, and uploading them here. So it's actually more advantageous to us to tag them, as it adds more diversity to the art that we get to enjoy.
