Take the Keisei train line from Tokyo to Haneda airport terminal 3. You will exit the train station on the 2nd floor of the airport (arrivals). Turn right after exiting and follow the signs down the passageway about 80 meters to the entrance of Hotel Villa Fontaine. Just past Lawson's convenience store is a counter called "Omotenashi Center". Bags can be stored here for up to a week at about 550 yen/24 hours. For international departures, backtrack to the train station and go up to the 3rd floor.
Directions (Google Map).
