definitely Narita City...don't waste valuable time going to Tokyo and back...(at least 2 1/2 hrs rntp)

There is storage (consignment) in both Tokyo terminals 1 and 2, near baggage claim, lower level... rate is by 24 hr period and by bag size...so be prepared to pull out a good US$7 for medium bag adn US$10 for larger bag.... but it beats logging it around... I don't recall lockers, but you can ask.

There is an ATM machine somewhere upstairs... if you need Yen.