As the bubble economy continued to fuel the rapid expansion of the Japanese car market in the second half of the 1980s, TMC's sales volume in Japan reached 2.12 million vehicles in 1988, surpassing its long-held annual domestic sales goal of 2 million vehicles. This goal had been set in 1978 for the long term with the assumption that the future market size in Japan would grow to 5 million units (excluding minivehicles). Subsequently, in its five-year plan beginning in 1986, TMC set the goal of achieving annual domestic sales of 2 million vehicles in 1990, but ended up achieving it in the third year of the plan, two years ahead of the goal.

In response to TMC achieving its goal of selling 2 million vehicles domestically, its Japan Sales & Marketing Group created the new "K250 Plan" with the goal of achieving sales of 2.5 million vehicles in 1993. In order to achieve higher customer satisfaction levels than competitors in all aspects and sustainably expand sales, this plan's goal was to achieve both a quantitative strengthening of sales capabilities and productivity improvements through streamlining and efficiency improvements in production. However, as the bubble economy progressed and the introduction of the consumption tax reduced automobile-related taxes, the Japanese car market continued to expand at a pace faster than had been expected. As a result, in 1990 when the market of cars (excluding minivehicles) in Japan reached the historical high of 5.98 million vehicles, TMC's actual domestic sales volume reached approximately 2.504 million vehicles, also achieving the K250 Plan ahead of schedule.