Public transportation ends fairly early. You will probably end up in a taxi. Good thing you will be in Haneda, as it is on the west side of the city, same as Park Hyatt. The cab fare should run about 6,600 yen. If you were coming in from Narita it would be closer to 30,000 yen. Nothing like a 400 dollar cab ride to really get your Japan trip off to a fun start!