The Okan is a Go competition conducted by the Japanese

Japanese people

The are an ethnic group originating in the Japanese archipelago and are the predominant ethnic group of Japan. Worldwide, approximately 130 million people are of Japanese descent; of these, approximately 127 million are residents of Japan. People of Japanese ancestry who live in other countries...

 Nihon-Kiin. There is a single game played between the title holder and a challenger. Unlike other tournaments which are open to all players, only players in the Nagoya branch of the Nihon-Kiin can compete. The winner's purse is a small 1,700,000 Yen ($15,000).

Winners

Player	Years Held
Sakai Toshio	1950 - 1955
Shimamura Toshihiro	1957 - 1965, 1974, 1975
Iwata Tatsuaki	1967, 1969, 1970, 1976, 1979, 1980
Hane Yasumasa	1972, 1978, 1983, 1992
Yamashiro Hiroshi	1977, 1981, 1982, 1984 - 1987, 1993 - 1996, 2000, 2001, 2005
Ogata Masaki	1988 - 1991
Nakano Hironari	1997, 1998
Hane Naoki	1999, 2002-2004, 2007-2009
Matsuoka Hideki	2006