The artist's name was in a tag, but someone has deleted it... I don't know why. His name is Yunioshi (ゆにおし), you can find more info about him right here: http://doujinshi.mugimugi.org/author/3588/Yunioshi/
YA-ZY is not his nickname or his pseudonym, it's the name of the circle wich he belongs, composed also by Orii Hiroshi and Momonose Harutsu, among others. But anyway, if you say so...
