Yes I think so. Guest registered name and check-in date must be included on the package. Most likely the package will be kept at the concierge near the main entrance at the lobby.

I highly recommend the train. The Tokyo subway is the envy of the world, plus announcements and stations are given in English, as well as Japanese. Your boys will love it! The Daiba station (Yurikamome Line) is right in front of the hotel. This line travels on a monorail and will give you spectacular views of Rainbow Bridge and the harbour. Board there and go to Shiodome (end of the line). Transfer to the Oedo Line which takes you right to HP! If you are worried about crowding, the only time we felt crowded was in Osaka during rush hour, but it only lasted a few stops. Use Google Maps and it will tell you exactly how much it will cost and where to board. A 40-minute taxi ride will be expensive, but it's your call.

I used the airport limousine which was very nice and economical. The hotel staff is top notch so I would imagine they would work with you. One of my favorite places in the world.