That Koa squad is adorable and marvelous. I want to hug them.
Also laughter for Sakuya's pose which brought this to "Dar Ass" pool #1214 ... come to think about it... that pose remind me of something I've already seen... what did it originated from?
I'm quite convinced this is the cover of the doujin compilation. The whole story so far can be found in doujin stores in Akiba with covers much like this one (though this one is the least fetish fuel of them all)
This is a cover page of the doujin. This whole series is being printed into several volumes and sold in doujin stores in Tokyo, and this is one of the covers (for the 7th book, to be specific)