Picture this: You¡¯re on a packed rush-hour train, listening to music on your headphones and reading your smartphone. It¡¯s too crowded to see your destination, and you miss your stop.

In the not-too-distant future, you won¡¯t even need to look up. It will be your nose that tells you where to get off.

Is that a whiff of beer hops? You¡¯re in Ebisu. Warm crepes? That¡¯ll be Harajuku. Smell an ocean breeze? Hamamatsu-cho awaits.