A doujin circle consisting of two members, "Prof Ootsuki" (ｐｒｏｆおおつき, lineart) and "Suigetsu" (酔月, coloring).
Circle name: 酔月工房 (Suigetsu Koubou)
https://www.pixiv.net/users/2645909
https://www.pixiv.net/stacc/suigetu_k
https://twitter.com/suigetu_koubou
https://twitter.com/intent/user?user_id=200345130
https://sketch.pixiv.net/@suigetu_k
http://portal.circle.ms/Circle/Index/10130683
http://www.doujinshi.org/browse/circle/5251/
http://twitpic.com/photos/suigetu_koubou