Artist, niconico video creator. Don't confuse this artist with Riyo (lyomsnpmp).
Japanese name: 優等生 (Yuuyousei)
Other names: すまーとくっきー, すまーとくっきーP
Circle name: 蒼色万年筆
https://www.pixiv.net/users/171184
https://www.pixiv.net/stacc/yuutousei
https://x.com/you2sei
https://x.com/i/user/89943642
http://dic.nicovideo.jp/id/4238317
https://seiga.nicovideo.jp/user/illust/1708177
https://www.nicovideo.jp/user/1708177
https://pawoo.net/@yuutousei
https://pawoo.net/web/accounts/240089
https://sketch.pixiv.net/@yuutousei
http://twitgoo.com/u/you2sei
http://p.twipple.jp/user/you2sei
http://twitpic.com/photos/you2sei
http://yfrog.com/user/you2sei/photos
