A little research when I saw the "Danger Angel" tag led to this actually being a character from an H-game. Lots of references to a CG set, but without going too in depth I didn't find much beyond that.
Oh, dear lord... My friend, Crystilmitsuru, possibly the greatest Roleplayer I have ever met, used this picture for one of her RP characters... I wonder if she knew it was from a hentai?
Though, the character was an angel, so considering that the hentai was "Danger Angel", maybe she knew...
Perhaps I should show her the picture from the front that was posted...