Oops, had this tagged yorukuro as that's whose site it appeared on, but it seems to be gift art and thus done by another artist. こずみっくさん? No link provided back to that artist's page though, unfortunately.

Link to the yorukuro blog entry: http://frozenbirch111.blog96.fc2.com/blog-entry-130.html

http://www.pixiv.net/member_illust.php?mode=medium&illust_id=2205369