Countless commentators both here in Japan and abroad have deplored the insularity of Japanese society. They lament the paucity of Japanese venturing abroad to study, teach or work. Japan's multinational corporations are regularly criticized for failing to internationalize their corporate management.
The implicit tone of much of this criticism is "why can't Japan be more like the United States?" The answer is simple. Japan's is an Old World East Asian society with Confucian, Buddhist and Shinto roots. It's no surprise it is different from a New World nation founded by dissenting Calvinists from Europe.
Comparing South Korea with Japan is far more logical and useful. Korea and Japan share the same cultural heritage. Korean civilization, and the transmission of Chinese culture through Korea, had much influence on Japan.