Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 7_0_2 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11A501 Safari/9537.53)
If you dont want a quick nap, get in the city. Find a neighbourhood and walk around. Then get back to the airport for the lounge.
Perhaps gp to the imperial palace/ginza. Then u can do sth else on the inbound