Japan isn't like the UK though.
You can still smoke in public (some areas are smoke free in Tokyo I think) and can still smoke in a lot of clubs/ restaurants so it's a different "smoking" culture than we have in the UK.
Also Japanese companies will NOT find it OK for you to wander off to have a chat will a work colleague about what was on telly last night/ christmas shopping or what Karen has done to her hair.
Nor can you wander off to make tea/ coffee.
You will be at your desk working 100% of the time. There will be someone in the office who will be responsible for making hot drinks/ refreshments for the team, even ordering everyone's lunch.
THIS is why the Japanese company is looking at this issue seriously.
I'm a non smoker but find people getting up and wandering around the other side of the building to "have a natter" to other colleagues about non work things or wandering off "to make coffee" take up just the same amount of time and if not more than someone "popping out for a fag" as at least they sometimes take documents to read whilst having a smoke.