Artist.
Japanese name: 神山 律 (reading is given as Kouyama Ritsu)
Circle name: スタジオ・アリエッタ (Studio Arietta) (the other members: Amakawa Takahiro, Eringi, Anonimasu and Hirotomo)
Site names: 神山の住所 or 神山の住家
https://www.pixiv.net/users/55147
https://www.pixiv.net/stacc/kouyama
https://twitter.com/kouyama_ritsu
https://twitter.com/intent/user?user_id=130162541
https://seiga.nicovideo.jp/user/illust/5540782
https://www.nicovideo.jp/user/5540782
https://pawoo.net/@kouyama
https://pawoo.net/web/accounts/140209
https://kouyama.fanbox.cc
https://www.pixiv.net/fanbox/creator/55147
https://sketch.pixiv.net/@kouyama
https://www.tinami.com/creator/profile/30024
http://kouyamaaddress.web.fc2.com
http://ritsukouyama.blog.fc2.com
http://studioarietta.web.fc2.com
http://www.stickam.jp/profile/kouyama
https://ameblo.jp/studio-arietta
http://pixiv.cc/kouyama
http://yfrog.com/user/kouyama_ritsu/photos