Nihon Ki-in

The Nihon Ki-in (日本棋院), also known as the Japan Go Association, is the main (non-profit) organization for Go in Tokyo, Japan. It maintains Japan's professional player system and gives diplomas for amateur rankings.
Professional Tournaments.
The Nihon Ki-in organizes many tournaments for professional players. The major title tournaments include the Kisei (棋聖, Board Master), Meijin (名人, Grand Master, hosted with Asahi Shinbun), Honinbo (本因坊), Judan (10-dan), Tengen (天元, Center), Gosei (碁聖, Master of Go), and the Oza (王座, King). There are also separate Honinbo, Meijin, and Kisei titles for women.