It’s the start of another day for an ordinary Tokyo salaryman. On a rain-drenched Monday morning, the engineer stows his plastic umbrella in the entryway of one of the many vast office buildings in the suburban metropolis that stretches between here and Yokohama. The umbrella locks into place and the engineer’s phone beeps.He straps a mask over his face, as everyone who enters the building must, and heads straight to the smoking room on the third floor, thinking about how much his habit is costi...