Saikouisen Nihon Pro Mahjong
From Japanese mahjong wiki
|Leader||Mr. Kiyoshi Niitsu, Representative|
The Saikouisen Nihon Pro Mahjong association (最高位戦日本プロ麻雀協会 Saikouisen nihon puro maajan kyoukai, informally called "Saikouisen") is a professional organization of competitive mahjong players.
As of June 2020, Saikouisen currently has 547 members.