Well, I began my search today. Using a thesaurus, I searched for just about every word related to this thread on google in Japanese (via google translate, though) and English, and on gelbooru and exhentai.
I found
nothing.
So, I'm now absolutely convinced that the only way to find pics like this are to track them down via brute force searching. So, searching tags such as seiza (traditional Japanese sitting, close to a kneel), kneeling, on_stomach, top-down_bottom-up, breast_press, arms_behind_back, and arm_support, alongside tags used in addition to them such as spread_legs (mainly used w/ the kneeling tag), -from_behind (for on_stomach, because they'd need to be facing you to prostrate themselves), looking_at_viewer, and looking_up on sankakucomplex's booru board, I began my brute-force search.
I was looking for pics in which the female looked particularly submissive, and seemed to be taking the submissive pose of their own will. If they seemed like they were not enjoying themselves at all, or were bound and forced in any way, I excluded them from my findings. Unfortunately, most of what I found is simple kneeling, or something close to it.
~Kneeling~
http://chan.sankakucomplex.com/post/show/1180218 (NOT loli, just flat)
http://chan.sankakucomplex.com/post/show/647071http://chan.sankakucomplex.com/post/show/1096673~Still On Knees, but More Than Just Kneeling~
http://chan.sankakucomplex.com/post/show/272234http://chan.sankakucomplex.com/post/show/226701http://chan.sankakucomplex.com/post/show/1905737http://chan.sankakucomplex.com/post/show/253120http://chan.sankakucomplex.com/post/show/1566114http://chan.sankakucomplex.com/post/show/845073http://chan.sankakucomplex.com/post/show/1596335 (the girl on the left)
http://chan.sankakucomplex.com/post/show/1593588 (so....flexible...!)
Hours of searching, and that's all I found. :/
I'll resume some other time.
