(1653-1689) Son (or younger brother) of Yasui II Sanchi. Is known to have played seven Castle Games, with a record of three wins and four losses. His most famous game was in 1683 with a two stone handicap against Honinbo Dosaku. This game is regarded as a lifetime masterpiece for both players, in which Shunchi wins by one point.
Game record: http://gobase.org/games/japan/misc/disks/dosaku/dosak24x.sgf