Originally Posted by
mherdeg
HND is close enough to the city that you actually have time, with 4 hours, to enter Tokyo if you like.
I would be very concerned about clearing customs and then having to get back through security in that time. 6-7 hours yes, but 4? Plus at night, its much harder to see things.
As others have said, the ANA lounge is open until the last *A flights are out. It has nice showers and some good featured sakes. Plus the always fun beer machine...