kamiyama_(kamyama)
Artist.
Japanese name: 神山 (Kamiyama)
Twitter nickname: 神山ビッパ (Kamiyama Bippa)
(Bippa is Bidoof's Japanese name. The artist jokingly said "I look like a bidoof.")
See also
* Pixiv account: http://www.pixiv.net/member.php?id=51421
* Twitter account: http://twitter.com/g_ya_ma
* Twipple photo images: http://p.twipple.jp/user/g_ya_ma