"Right inside the terminal it’s the most convenient place! We drop our bags and catch a train right from the terminal into various neighborhoods of Tokyo to explore. Then train straight back to the airport and up the escalator to the hotel. Rooms are quite small but who cares. Book on an aggregator site like Expedia because it’s quite expensive in the hotel website. Just outside the hotel in the terminal is a convenience store for a bottle of wine and downstate is a great little restaurant for noodles and dumplings.
No worries about hauling luggage outside the airport or through weather. Often we stay in the airport hotel 2 nights to just explore the city on the way from the USA to SE Asia and back"