For me the biggest one was not smoking on the street. Possibly it's because it happened just when I arrived (2007). Everybody and their dog would be smoking while walking down the street. One day a sign went up that showed a picture of a person with a cigarette and a child. It had a caption that read, "A cigarette butt is held at eye level for a child". Literally the next day smoking on the street stopped. I very, very rarely see it any more.

Interestingly, perhaps bouyed by the success of the cigarette sign, on the train they had signs of "Do it at home" with pictures of people doing makeup, or whatever. Everybody ignored it :-).

More generally, apparently sexual harassment used to be common in the workplace. I never actually saw anything extreme, but I did see a massive change in attitude. One day guys would be talking about inappropriate things at work without anyone ever saying anything and the next day when the same thing happened the section chief would be yelling at them about sexual harassment. It was literally night and day and it wasn't like there was an announcement or anything. It just went from being tolerated to not being tolerated.

I often see things on TV that makes me wonder if the government is kind of sounding people out on stuff. For example, one day they had a piece on Korean schools for ethnic Koreans whose family members were essentially abducted to Japan during WWII. The children and grandchildren (and probably great grand children now) for many of these people are still in Japan. Because the Japanese law doesn't allow dual citizenship, these people have to choose between Korean and Japanese citizenship. If they decided to choose Korean citizenship, they get permanent resident status, but not citizenship. This is considered a pretty big problem with a lot of people and so it's been a question for literally generations about what to do: should these people be granted dual citizenship? What about school systems that include Korean culture? How much should be paid by the government etc? It's a horrible mess and, of course, in Japanese style virtually nothing has been done about it (very weird to be born in a country and not have citizenship of that country)! But this NHK program was very sympathetic to the plight of these people, so it made me think that maybe a move was afoot (the NHK is not as arms length from the government as the BBC is from the UK government...). But not so far anyway.