|Leader||Yukio Oshida, Representative|
Mahjong Union (麻将連合, Maajan rengou; also known as µ! (mu / myuu)) is a mixed professional and amateur organization of competitive mahjong players.
As of October 2018, MU has 23 professional members. MU also has 40 "touring" members, and 7 female "touring" members.
MU are apparently highly implicated in encouraging more grassroots promotion of online mahjong players with its "Three Arrows" initiative.