Let me emphasize that the last two posts tell it like it is. Forget the town of Narita, so don't bother with Mike Newman's web page. Go into Tokyo, and take the train, not the bus. Incidentally, the per bag check fee is either Y500 or 800 depending on ths size of the bag.

Harajuku on a Sunday afternoon is great but ONLY if the weather is decent, otherwise the main tourist attraction (mostly, but not entirely, teenage girls) doesn't show up.

Also make sure you get some yen from an ATM. Credit card acceptance is not universal and foreign currency will not be accepted. Change back what's left at the airport.