Artist. Images are generally signed キ~の~ (with the キ in a circle), followed by the image number and the date.
Name: けいじえい (Kei Jiei)
https://www.pixiv.net/users/5021528
https://www.pixiv.net/stacc/momoego
https://twitter.com/momoegox
https://twitter.com/intent/user?user_id=765352992916836353
https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG51691.html
http://doujinshi.mugimugi.org/browse/author/6201/Kei-Jiei
