You certainly have plenty of time to head into Tokyo, have lunch, and do some exploring. Pick one or two areas that are interesting to you, and head there. A good option is the Asakusa area, an especially interesting neighborhood that includes the Sensoji temple. You could also take a river cruise, as well. Asakusa is easy to reach from Narita -- take the Keisei skyliner train to Ueno, then either walk or take the subway to Asakusa. A good place to eat in that area is Maguro Bito, a conveyor belt sushi spot that offers good quality along with a welcoming environment for non-Japanese speakers/readers.

I suppose you could take the bullet train (called the Shinkansen), but that would be very expensive. Even a very short trip, say from Ueno to Omiya (about 20 miles), costs around $60 round-trip.

Or, far faster and easier, just take the bus into central Narita town and visit the Naritasan Buddhist temple complex. It's a marvelous asset - peaceful, beautiful, historic, with wonderful gardens, just minutes from the airport. In front of the temple entrance is a great shopping/eating area with numerous lovely old buildings, markets, shops, cafes. I'm always amazed at how many thousands, maybe millions, of people have layovers at Narita unaware of this treasure just a few minutes from the airport.

Photos: http://www.flickr.com/photos/58865367@N06/sets/72157632732039352/

There are two companies with express trains to Tokyo, but it is not Shinkansen.

we spent our layover in narita town and quite enjoyed it... the airport also runs some tours from the airport to local areas.. check at the info desk in the lobby.

Thank you! This is all certainly good news. We've been planning our SE Asia trip, and I suppose I am getting a bit lazy in researching these last details. I thought the express (Shinkansen?) was basically the only option (had heard it was expensive), so glad to know there are other options. Thank you all again!

No, the shinkansen is JR's high-speed rail system in Japan, which for the most part is separate from the "regular' rail system in Japan.

Two train systems go to NRT. JR and Keisei - neither are true highspeed ones. Both have their own "express" trains going into Tokyo. JR's service is NEX to stations like Tokyo Station. Keisei's service is called Skyliner and goes to Ueno.

Best to have two plans as you may be exhausted. Also, if your flight is delayed or if it takes a long time to clear immigrations (as it often does).

Plan one to come into the city.

Plan two to spend time in Narita city. We just went recently on our way to a departing flight from Narita and were surprised at how charming the city is. There is a famous Narita temple that is worth visiting and plenty of unagi restaurants.

I like Don's reco of the Asakusa area and Sensoji Temple.It will definitely give you a sample of the Tokyo scene with a destination that is transportation friendly to your situation. Some options on getting to Asakusa and back include the Keisei Liner, Keisei Limited Express and the JR NEx line + short subway explained in detail here:

http://www.japan-guide.com/e/e2027.html?aFROM=2027_3004

So many places to eat lunch in the area. In the Sensoji Temple area there are yatai stalls serving all kinds of Japanese comfort foods with tables set up for you outside to enjoy a nice lunch.

If you plan to stay just in Narita town you can check this page for things to do and how to do them in Narita.

http://www.mgnewman.com/Naritax/

Aloha!

I have spent my eight hours in narita several times, and always enjoy it. You can take the short train ride there, walk down to the temple,have lunch, even head out to the shopping mall for a little while if you need some last souvenirs. There are lots of places to eat there too.

One time I was with some friends on the layover. While two of us visited Narita, the others went into Tokyo, where they went to an for a bath, had lunch and wandered around Sensoji.

I recommend you do buy a round trip ticket, so you won't have any issues with lines on your return. Also, keep track of your station and the location of the return airport platforms. This past November there was a lot of construction going ou around the station and we had a bit of trouble finding the correct platforms as there are now two separated stations.

In the post above, it was supposed to say "they went for a bath at a sento (neighborhood community bath), met up with a Tokyo Fodorite, ..."

I do not have suggestions right now but your going for most amazing experience. All the best!