I just did this trip last week and would strongly recommend the Friendly Limousine Bus. You'll be quite tired after the long flight and the bus is so super easy. You buy the ticket just as you exit customs, go out the door and take the bus right there. It then drops you off right at the hotel. It may take a little longer than the train but you aren't lugging anything around, don't have to go up and down stairs, be alert on the train for your station...

I've done both and the bus is way easier.

On the return trip, if the bus from your hotel doesn't leave at a convenient time (ie makes you get to the airport too early), then find out what the bus schedule is from neighboring hotels.

http://www.limousinebus.co.jp/e

Alexandra