Oteai
From 1927 through to 2003, the Oteai was the tournament in which Japanese professionals earned their ranking. Games were played throughout the year according to a regular weekly schedule, and the players received a fee for every game played. An unusual feature of the Oteai is that all games were played without komi.
John Fairbairn wrote an article about the early Oteai: http://web.archive.org/web/20110608002109/http://www.msoworld.com/mindzine/news/orient/go/history/oteai1.html
See also: