I don't know what's happening in Tokyo and there is always a certain fashionability about smoking amongst the young on the bar and nightclub scene.
But its pretty rare given that in some countries smoking rates are below 20% of the adult population.
The collapse of communism caused an epidemic of drunkeness and the current great recession in the US is also shortening life spans, so economic crisis and forms of risky behaviour are probably correlated.
'Forget it Jake. It's Chinatown'