Transformers: Operation Combination was Takara's eighth and final installment in Japanese Generation 1. The series included only ten sets, though six were combiner giftsets with five or six figures, and the others were versus 2-packs.
The bulk of the line were new Micro Transformer Combiners, six-member teams that combined by connecting to various adapter pieces. The adapter pieces could be recombined to form some sort of vehicle or weapon for use by the individual members. The set also included redecos of Bruticus and Defensor, but with new names and identities. The remainder of the line was filled out by versus sets of the Jet Corps and Road Corps, which were identical to the small members of European G1's Predators and Turbomasters, respectively.
Due to low popularity and sales, many sets from Operation Combination are exceedingly rare, especially Battle Gaia and Guard City. Surprisingly, many of the Micro Transformer Combiners were reissued as part of Takara's 2002 Micromaster toyline, greatly reducing their price on the secondhand market despite the originals' rarity. Even so, Operation Combination spelled the end for the Transformers brand in Japan, even though it would live on in Europe. The franchise would not be seen again in Japan until 1995, with Takara's fleeting attempt at reviving the series with G-2. However, Takara would not stand idly by in the transforming robot market, instead choosing to focus on its Brave Series from 1990 to 1997.