The day room by Gate 25? is not bad. I've crashed there for a few hours before and it's pitch black in there when you turn off the lights. Since you have such a long layover, I would visit the United lounge also. The food is better at ANA lounges especially when they have the sushi bar but I like the United lounge showers better. 24left has a good suggestion, it was so humid there last week, I ended up taking two showers within three hours!