From left: 2nd cousin of Grandmaster Yoon Byung-In ; Yoon Byung-Bu, Grandmaster Kim Soo, and 1st cousin of Grandmaster Yoon Byung-In ; Yoon Byung-Moon. Yoon Byung-Bu (86 yrs. old) grew up with Yoon Byung-In in Manchuria and gave GM Kim Soo a lot of good information and GM Yoon Byung-In's letter from N. Korea.