In the 1963 Japanese cycle parts manufacturers banded together to form JASCA (Japanese Sports Cycle Association) in order to promote their products through joint advertising.
In 1969 JASCA split into two organisations, JBM (Japanese Bicycle Manufacturers) which was based around Shimano, and JEX (Japan Bicycle Parts Manufacturers Group for Export Promotion) which was based around SunTour.
In addition to Shimano, the JBM group consisted of Araya, KKT, Sakae Ringyo (SR), Takagi, and Tange.
However, as Shimano grew, it expanded its range to include components that competed with the other JBM members. This led to inevitable friction in the group and JBM broke up in 1984.