Artist. Not related to Kristoph Gavin.
Japanese name: がりゅーん (Garyuun)
https://www.pixiv.net/users/466026
https://www.pixiv.net/stacc/ryuujin117
https://twitter.com/aoriprpr
https://twitter.com/rurutanprpr
https://twitter.com/intent/user?user_id=606345002
https://twitter.com/intent/user?user_id=3456914052
http://www.nicovideo.jp/watch/sm18098696/
https://sketch.pixiv.net/@ryuujin117
