Crowded, big on conformity, and at times quite xenophobic (they might not say it to your face, but if you know where to look...).
Still, the low crime rate is appealing (though somewhat offset by their high suicide rate), you can get beer in vending machines, the cities are kept remarkably clean, you can get beer in vending machines, their public transportation system is amazing, and hey, did I mention you can get beer in vending machines? It's also one of the few places in Asia that I've been to with reliably clean tap water (don't even get me started on the things I've seen in Thailand). The way they treat customers and patrons in shops and restaurants is nothing short of exemplary. It's really a refreshing change of pace from the customer service I've seen in parts of the U.S. and Europe where you're treated with either indifference or passive hostility and the service staff won't even give you the time of day if you look even remotely foreign (I'm looking at you, Paris). It's a shame tipping is considered an insult there, they really do deserve it for all the attentiveness they show.
^Happa in Hawaii, I go there to visit family every other year or so.
Edit: On a side note, it's nice to see that the Japanese find otakus just as annoying and whinging as we do in the states. It's also fun to know that they hold just as many stereotypes of the west to heart as we do of them. I had a cousin there who had genuinely believed in the whole "All of America is Texas" misconception (believe it or not, we all don't wear ten gallon hats and wave around six shooters while riding horses on our gas guzzling hummers to work at the cheeseburger manufacturing plant in Hollywood) and wondered if I've ever participated in a cattle drive before. Luckily I was able to set him straight by telling him that unlike on the mainland, in Hawaii we just wear grass skirts and live in grass huts and ride surfboards to work at the pineapple plantations.