Arriving at Narita International Airport

I am going to be traveling via American Airlines to Narita and will be traveling to either Hiroshima or Iwakuni, what is the best way to go and about how many hours will it take in travel time?

Heather you didn't say if you had a preference for train or plane. Time of arrival is also relevant to what may be available. Look at http://www.hyperdia.com/cgi-english/hyperWeb.cgi
If you want to travel by train type in Narita airport, Hiroshima and make it via Shinagawa ( passed point ). That will make your search results very much simpler...just look for the simple two train option.

1) By train:
http://gutereise09.blogspot.com/2008/09/train-connections-be...

Transfer guide at Shinagawa or Tokyo:
http://gutereise09.blogspot.com/2008/07/transfer-from-narita...

2) By air:
You might fly from Tokyo Haneda to Hiroshima. You can fly JAL for 10,000 yen per segment on the airpass.

http://www.jal.co.jp/en/dom/
http://gutereise09.blogspot.com/2008/07/japan-airpass.html

http://www.limousinebus.co.jp/en/timetable/narita/hanedaapt_...

the fastest way would be to buy a connecting ticket from haneda airport and fly to hiroshima from haneda. you might be able to catch a shuttle flight from narita to haneda but most likely you would need to take the narita express train or a limo bus to tokyo and then get on a train to haneda. if you do the train thing it'll take about 2 hours or so to get to haneda.

if you don't want to fly after narita you can take a shinkansen from any of the major tokyo stations and that trip will take around 5 hours if i remember right. it's expensive. there is not much room for luggage. if you have any make sure you have it sent to your destination ahead of time at narita via yamato kuroneko or something before you leave.

you can also take a night bus leaving from the major tokyo train stations that will be much cheaper but less comfortable. it takes all night to get there but as i said it's much cheaper.

hope this helps.