Artist.
Japanese name: がんじゅーい (Ganjuui, the artist uses this spelling: "Ganzyu-i")
https://seiga.nicovideo.jp/user/illust/16109864
https://www.nicovideo.jp/user/16109864
https://www.tinami.com/creator/profile/3541
http://ganzyui.blog.fc2.com
https://www.pixiv.net/users/361799
https://www.pixiv.net/stacc/ganzyu-i
https://twitter.com/ganzyu_i
https://twitter.com/intent/user?user_id=234743712
https://sketch.pixiv.net/@ganzyu-i