The keshi it includes are monochromatic and derived from the Kinnikuman (キン肉マン) anime and manga franchise, whose primary motif is professional wrestling.
Starting in Japan in 1983, Bandai's Kinkeshi line was licensed in 1985 to Mattel for marketing in the United States and Canada, where wrestling had become popular.
The figures were distributed in clear, blister-packed random four-packs, semi-opaque garbage can 10-packs, and 28 packs featuring non-random assortments.
Some of the figures were sculpted to resemble popular wrestlers who had competed in Japan such as Terry Funk, Dusty Rhodes, Abdullah the Butcher, and Jushin "Thunder" Liger.
In addition to packs containing only figures, there was a mail-away poster, a "Battlin' Belt" display case, and two games released that made use of the M.U.S.C.L.E.
The Hard Knockin' Rockin' Ring came with two exclusive flesh figures not released in the regular line of toys, a slightly smaller version of #141 (Muscleman) and a Terri-Bull.
The Sesto Fiorentino based GIG Spa company mixed three different imported keshi lines to create its own franchise.
Around the same period, the Exogini line was marketed in France as Cosmix by El Greco "Un hellenistic crafts S.A.", a Greek manufacturer, to Action GT (Action Games & Toys Inc.), a North American company, and imported to France by Idéal Loisirs S.A., a famous French toy distributor.
[citation needed] However, France was the only country, outside of the franchise's native Japan, to broadcast the Kinnikuman TV series (localized as Muscleman) by that time.