I assume that you mean the Four Seasons Marunouchi, and not the Chinzanso hotel that ceased being a Four Seasons hotel this year?

If the former, it's an excellent hotel, and the only thing I would consider is perhaps splitting up the trip to include another luxury hotel, as there are so many good ones to be found in Tokyo. Within walkable distance alone there is The Peninsula, Shangri-la, and Mandarin Oriental, all of which offer spectacular facilities that offer an experience that's a little different than what's available at the Four Seasons.