After WW2 the US went to Japan and helped rebuild. The rebuild meant Japan had the most modern equipment available in the day. Their quality was not good at the beginning, and a stamp saying "Made in Japan" had a negative connotation. During the 1964 Olympics the events were timed by the use of Seiko time peaces. That was a positive event for Seiko and manufacturing in Japan. Evidence of their improved production of critical products.
Soon the automotive manufactures began shipping cars to the US. It took a while, but eventually the population in the US became aware of the long life the Japanese auto engines lasted, and the mileage they got. Fit and finish of the body parts were smoother and fit better then Ford, Chev, Chrysler and all the others. This awareness is when US auto manufactures had to step up to compete. Soon all car dealers sold their favorite American model and at least one Japanese model.
The race was on! Until that time if a Japanese (or other country made car) was on a auto union parking lot it would be "keyed" at the least and usually tipped on it's side. There were signs at the parking entrance, "No Foreign Vehicles allowed". They meant it!
Kubota made industrial pumps and engines for just about everything. Their tractors were designed for use in rice paddies. That is where "rice" tires were used. That is where the drain plug in the bell housing came into being. Those tractors worked in deep doo doo!
In the early '70's when Kubota brought small tractors to the US their competition was Yanmar and a couple of others but you know who won out, Kubota and JD. (JD's were built by Yanmar) By 1980 there were no diesel engine tractors made in the USA.