Hey, just changed the wallpaper to this picture. I don’t know if this particular wallpaper is from an anime, manga, or hentai but I liked it. All I know that the illustrator is Misato Mitsumi who authored the anime ef. If you guys know what art this wallpaper from, please let me know. In the meantime, you can enjoy and download this particular wallpaper:
Randomness Thing 
Misato Mitsumi is a very well known illustrator, her fame got lowered a little since Carnelian’s Idolization but she’s still getting really well paid :) Original character designer for Company “Leaf”, worked on Pia Carrot 1, 2, Comic Party, etc.
BTW This wallpaper is from a Visual Novel called “December When There is No Angel”, a game produced by “Leaf” Both characters are Asuna Asou (short hair) and Yukio Samadera ( Twin tails).
Misato Mitsumi always works together with Tatsuki Amaduyu, and also works with Nakamura Takeshi and Kawata Hisashi. You can expect great art from them.