List of Japanese organizations
The following is a list of organizations in Japan, pertaining to Japanese mahjong. As of October 2018, there are 1528 professionals among the Big Five organizations promoting modern riichi mahjong (not counting 101).
| Organization | Kanji | Inception | Member count |
|---|---|---|---|
| 101 Kyougi Renmei | 「１０１競技連盟」 | 1982 | (23) |
| Japan Professional Mahjong League | 日本プロ麻雀連盟 | 1981 | 610 |
| Mahjong Union | 麻将連合 | 1997 (approx.) | 70 |
| Nihon Pro Mahjong Kyoukai | 「日本プロ麻雀協会」 | 2001 (2010) | 382 |
| Real Mahjong Unit | RMU | 2007 | 57 |
| Saikouisen Nihon Pro Mahjong | 最高位戦日本プロ麻雀協会 | 1976 | 409 |
| ZOO |