It is not so hard to live without a car in the rural areas. They are well served by buses, which will take you to the local train station. I traveled all over the countryside for mountaineering/skiing/etc., including some extremely rural areas, almost entirely on public transit. It is a special pleasure to take a bus to the start of a week-long ski mountaineering trip, and then take the train back.

However, I agree fully that Japanese people love to drive around -- mostly for pleasure rather than necessity. This is a country with seven international car companies, after all.

I want to introduce several examples of real train/walking based cities, instead of the mediocre Portland.

Most countries in the world import almost all their fossil fuels. Not many countries have meaningful fossil fuel deposits. Japan is no different there than France, Italy, Thailand, Korea, Argentina, Spain, India, etc. etc.