Originally Posted by
Loran
Sorry if I wasn't clear. Basically I want a shower and nap mid-way through my layover. So I'd like to stay airside for a couple of hours in the morning (I'll have my connecting boarding pass, so I can go through transit security), then leave airside and go through immigration and customs to nine hours.
Is this possible, or once I'm airside am I stuck there?
I think you'll find conflicting reports if you search these pages - I'm sure I've seen at least one post that said it was possible to leave airside departures area and go through immigration into Japan. And I'm sure I've seen another post from someone who was denied permission to do this.
If I were you, I'd go into Japan as soon as you arrive. Once landside, you can find shops, day rooms at airport hotels, showers (at hotels or in the airport terminal), and anything else you might need. The only thing you won't have is an airline lounge with free refreshments.