One of the major changes that I did notice in Japan was the societal change in people smoking. During the time I lived in Japan, people smoked in restaurants, cafes, in offices on railway platforms, something I found difficult to deal with at times, since I had grown used to the lack of areas to smoke in public, in Australia. I also come from a long line of non-smokers, extended family as well, no grandparents. aunts or uncles who were smokers, so my tolerance level for cigarette smoke is very low.
I can remember how shocked I was to walk past a really nice cafe that had decking out onto the footpath, I looked inside to the groups of young women all sat at tables with lit cigarettes and the ashtrays were overflowing with cigarette butts. (I had led a very sheltered existence in my land of non-smoking everywhere!) Fortunately for me shortly after I arrived in Japan, so did Starbucks, and they have a strict no smoking policy in all their branches. So I became a regular, in Japan at the time it was quite ground breaking, a coffee shop that didn't allow smoking.
Fast forward many years and Japan still has the non-smoking Starbucks but now Japanese chains also offer smoking and non-smoking areas so you do get asked when you enter. (An aside, I do know how to say non-smoking in Japanese "Kin'en" but one look at my non Japanese face and the servers stammer out 'non-smoking, smoking?' Sadly no Japanese language practice for me!)
The streets also seemed not to have people smoking as they're walking around and then I found out why. There are designated smoking areas on the footpath for smokers, and Japanese being the rule followers they are, only smoke in those areas. Here's one in Harajuku, it's a low photo as I didn't want to have people's faces in the picture.
This was quite a fancy smoking stop, the others I saw were just basically a sign and people huddled around a rubbish bin smoking.
Train station platforms no longer have a designated smoking area, (that I saw), my Tokyo hotel (which was new and had only opened in January 2015) was non-smoking but it had a room on the ground floor labelled 'Smoking room' for those who couldn't get through a stay without a cigarette. The Shinkansen (the bullet train) still has smoking carriages, just one in the non-reserved section, 4 non-smoking. When you make a hotel reservation, hotels will ask a smoking or non-smoking room?
It seems Japan is adjusting to smoking being an antisocial activity and perhaps the high level of people who smoke will go down as the years pass. (In my 'I live in Japan years' the percentage of Japanese who smoked was really high over 50%, Australia at the time was down to less than 30%)