From the quiet of a monastery in Koyasan and the serene beauty of Mount Fuji to a winter's evening in Tokyo, there is quite the paradigm shift! Tokyo amazes, it takes your breath away, but it doesn't stop for you, it just sweeps you along for the ride. Best to strap in and ride the wave.
Shinjuku Station is a great place to observe metropolitan Tokyo breathe and move. The crowds, their order in all that noise and traffic, the enormous horde of commuters who walk across what must be the busiest traffic signal in all of Tokyo—these sights just take your breath away.
And if you want to spend a few hours like a nocturnal animal underground, Shinjuku Station is just the place for you. You'll find tons of shopping at the Odakyu and Keio malls, plenty of fast food joints, and the most confusing floor plan known to man.
It took me at least two hours to figure out how to get to my platform to catch the subway line back to my hotel. Shinjuku is the hub for at least four Japanese subway lines and it has multiple subway levels, so get ready to get lost! It is a fun ride.
The neighborhood around Shinjuku is great for grabbing a coffee, seeing the neon skyline of Tokyo, and doing some street shopping. Be prepared to spend some time there.