Artist, nicoLive user.
Japanese name: 薄井硫酸 (Usui Ryuusan)
Old name: 稀硫酸 (Kiryuusan)
Circle name: 化学室｡ (Kagakushitsu.)
https://www.pixiv.net/users/558337
https://www.pixiv.net/stacc/usrs444
https://twitter.com/usrs
https://twitter.com/intent/user?user_id=59831683
https://usrs.booth.pm
https://seiga.nicovideo.jp/user/illust/403926
http://dic.nicovideo.jp/id/4153430
https://com.nicovideo.jp/community/co35169
https://dic.nicovideo.jp/u/403926
https://www.nicovideo.jp/user/403926
https://pawoo.net/@usrs
https://pawoo.net/web/accounts/139947
https://usrs.fanbox.cc
https://www.pixiv.net/fanbox/creator/558337
https://sketch.pixiv.net/@usrs444
https://skeb.jp/@usrs
https://www.tinami.com/creator/profile/9233
https://ask.fm/usrs_444
http://kgkst.blog.fc2.com
http://kgkst.web.fc2.com
https://privatter.net/u/usrs
https://www.youtube.com/channel/UCNj422QYOx5pAspXnlPii-w
https://marshmallow-qa.com/usrs
http://photozou.jp/photo/top/325858
https://www.pixiv.net/stacc/yuuki_444
https://odaibako.net/u/usrs
http://twitpic.com/photos/usrs
