Of course they were impressed you could write kanji, just as we're impressed when a trained monkey can play an organ-grinder. That's simplistic, of course, but it highlights the same thing: foreigners who can speak Japanese or do things the "Japanese" way are seen with a sense of wonder, but they are never fully accepted. You can live in Japan for years, even be born in Japan, and still not be considered Japanese if 1) your grandparents, great-grandparents, great-great-grandparents were Korean or Chinese or Brazilian or 2) you leave Japan for too long.

Of course you made meaningful relationships that didn't end as soon as you got on a plane. It's absurd to think otherwise, and of course you met people who grumble humbly about Japan's past atrocities.... but that is not the society at whole, and we are discussing the society as a whole. The Japanese government still claims the Rape of Nanking never happened... it's not taught in Japanese schools, it's taken out of Japanese textbooks. Compare that to Hiroshima.

The phenomenon is well documented in Japanese anthropology and studies of culture and custom. And while I can make no value judgement about your stay there or your friendships, it's possible they were seemingly so agreeable because they were afraid to tell the pushy, dominant American that h/she was being impolite. For the majority of Japanese, politeness is of utmost importance.... and something that would be perceived as assertive or forward in our culture is blushingly aggressive in theirs.

I love Japan. I think the Japanese, as a whole, are a wonderful example of countrymen who have opened their arms to the world. But while they have opened their arms, they have not opened their hearts. I find many more Japanese people who listen politely and agree with the "new" ideas I bring them... and then continue to do it just as they have always done. That is the crux problem of the Japanese; they are open, yet unaccepting... polite and humble while never revealing their true feelings. Yes, they may reveal them to you, as a very close friend, but to others, their countrymen, the one with whom open dialogue is the most important, they hide their true hearts and feelings. This is the Japanese way.