Yamamoto Genkichi(1763-1825) reached 5 dan (6 dan after his death). In 1801 played 21 game match with Hattori Inshuku on BBW handicap and lost 10-11(8-6 on black and 2-5 on white).
In 1803 he played and won (6 wins and 3 losses) a match against Honinbo Genjo .
In 1809 he played and tied (5 wins, 5 losses, 1 jigo) a match against Okunuki Chisaku. In a previous match in 1803 they won 5 games each, but Genkichi previously forced Chisaku to the handicap of playing black in all games (this is a incomplete list of their games).
149 games of Genkichi (he later assumed the name of Dosa) are known (download the collection -games are in Chinese, code gb2312- from flygo.net site). On the flygo.net site there is also the complete list, in Chinese, of Genkichi's games.