Sada Atsushi (佐田 篤史, born December 24, 1995) is a professional player of the Kansai Ki-in.
He's won an award for most consecutive victories. He also received the Risen Prize and Nagai Prize. 
The site https://osaka-kodomoigo.com/ is listed as his "ＨＰ・ブログ等", which could be guessed to mean HomePage.
- Kansai Ki-in player profile
 Interpreting the text 利仙賞 2回 連勝賞 1回 永井賞 3回. Not sure whether to interpret 回 as edition or place (or something else) in this context. The Risen Prize? (利仙賞) is a Kansai Kiin award named after Sekiyama Riichi, who took the name Risen as Honinbo. The Nagai Prize? (永井賞) is probably named after Go author Nagai Todonori?, who cowrote the book Igo Hitoriannai in 1889, since he's the only person of that name mentioned on SL.