Another option is to google "airport limousine bus haneda". They offer service from the airport to various hotels at a very reasonable price. Not as convenient as a taxi but much less expensive and more convenient than taking public transport with luggage. We've done this from the Conrad to Narita and Haneda at different times. I believe the route would be Hibiya, Ginza, Shiodome. You can email the hotel with more questions or to ask which route to take - they might even be able to supply you with the schedule.