A fascinating tool for comparing countries is Hofstede's cultural dimensions theory, which looks at power distance, individualism vs. collectivism, uncertainty avoidance, masculinity vs. femininity, long-term orientation, and indulgence vs. restraint.

https://www.hofstede-insights.com/country-comparison/japan,s...

I computed the cosine similarity between Japan, SK, and the USA to get:

Japan-SK: 0.933

USA-Jap: 0.8315

USA-SK: 0.670

So it does appear that Japan is more similar to the US than South Korea using this metric.

Well, the Japanese were once called Yankees of the Orient...

I think the least surprising result of all is that Japan and South Korea are both more like each other than they are like the United States.

Pretty much. They both are. They stand in stark comparison to everywhere else in Asia.

You mean South Korea. There is no country called Korea.

Strictly speaking, there's no country called South Korea - there's the Republic of Korea and the Democratic People's Republic of Korea, both of which make a territorial claim over the whole peninsula.

You mean the 'Republic of Korea'?