Originally Posted by
lobsterdog
The area around that hotel isn't really interesting for wandering around, especially for eight or nine hours.
+1. Not much in the immediate vicinity of IC Tokyo Bay. OP could go to Odaiba by Yurikamome, which is probably the easiest fun place to get to. A lot of things don't open till 10a or 11a in Odaiba, though. OP could go check out Tsukiji before that to kill time, or have a long breakfast at the hotel.
On those late-night TPAC flights that arrive super-early in Asia, I tend to sleep a fair amount even in Y. Of course everyone's different, but it's possible you'll arrive with enough energy to be able to have a full-go on your first day in Tokyo.