Tokyo is serviced by two major airports, Narita International Airport (NRT) in Chiba prefecture which handles mostly international air traffic and is the arrival point for the majority of foreign visitors, and the more centrally located Haneda Airport (HND) which handles mostly domestic air traffic and a smaller number of international flights.
There are plenty of facilities on Narita airport to make your transit comfortable, like showers, nap rooms, a capsule hotel, baggage delivery service, a post office, and lounges. One thing you might want to do while you are at the airport is renting a pocket WIFI, which will keep you connected to the internet throughout your trip.
The airport consists of 3 terminals, of which terminal 1 and 2 have their own train stations from which you can get to Narita city and Tokyo. Taking the train into Tokyo is one of the easiest ways to get there, but you can also opt for the limousine bus or if you have a high budget for a taxi. Please keep in mind that taking a taxi from Narita airport to a hotel in central Tokyo will easily set you back around 200 dollars for a one-way ride.
Narita Airport is located about 60 km outside of Tokyo, in the city of Narita. If you have a layover in Narita of at least 4 hours you can visit nearby Narita city which is only a train ride of 15 minutes away. If your layover is at least 6 hours it would be a waste not to take this opportunity to visit Tokyo as the fastest train takes only a little over one hour to bring you to the middle of this bustling metropole. If you really want to make the most of your layover time, consider hiring a private guide who can either pick you up from the airport or meet you at Tokyo station and show you some of the best highlights and local hidden treasures.