yamamura_hiroki
This artist is a professional animator who worked closely with studio Shaft (company) on series such as Sayonara Zetsubou Sensei, Mahou Shoujo Madoka Magica, and the Monogatari_series mostly as chief animation director.
Prior to that (under the pen-name "Murayama Takahiro") he was the illustrator of ero-games such as Usaneko and GHQ: Chihiro Gakuen Ura Gakuensai from about 2003 - 2007.
Before that, he was a doujin artist with the same pen-name styling himself as "Studio Pakli" and published a few doujinshi with Suzuki Amaharu in the "Jibaku System" circle and others from about 1999-2003.