usagi_koushaku
Artist.
Japanese name: ウサギ公爵 (Usagi Koushaku)
Old names: 紳士ウサ。 (Shinshi Usa.) or "CROW"
See also
* Pixiv account: http://www.pixiv.net/member.php?id=3608744
* Niconico account: http://www.nicovideo.jp/user/36907761
* Niconico Seiga: http://seiga.nicovideo.jp/user/illust/36907761?target=illust_all
* Twitter account: http://twitter.com/duke_bunny