Are you kidding me? The Japanese learned by imitation in the 50s and 60s and then became
master innovators from the early 70s on. That's what put them on the map!! ... as in coming out with new and unique designs that nobody else had even dreamed of. This is especially true in the motorcycle market through the 80s and 90s .... crazy stuff going on each year. By contrast, the Americans had the Harley which was basically the same since the early 1900s. The US auto industry sat on their fat butts doing little more than nothing which is how the Japanese got their automotive market share. People got tired of buying junk that didn't work.
The Americans embraced turbo engines for quite a few years ... well, the Buick V6 Gran National was a great design ... in a Grandpa kind of car. and the 80s Dodge had some K car turbos cars .... and a pickup truck which was kind of unique. However, the Japanese had turbo cars too, plenty of them. How about the turbo Hilux Toyota 4x4 trucks in the 80s, and the 1990 MR2 Turbo and then the wicked fast, totally over engineered Toyota Supra twin turbo ....

And there there was Mitubishi. I'm sorry, but Honda alone doesn't represent Japan.
Japan is all about innovation in everything they do, electronics, appliances, optics, cameras and automotive, probably more than any other nation on the Planet.