topcat - take a look at this link ...
http://www.narita-airport.jp/en/trav...ist.html#hotel

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Aircraft operating hours is between 6:00 a.m. and 11:00 p.m.. Customers are not permitted to remain in the passenger terminals outside aircraft operating hours. However, under special circumstances, for example when an aircraft arrives after public transport stops operating, customers may be allowed to sleep in designated areas. Moreover, customers catching early morning flights are advised to use nearby hotels and accommodations around the airport.
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But also take a look here ... might help or might not ... but it seems the police do come around at a certain point.
http://www.sleepinginairports.net/li...o&terminal=NRT

Good luck ... sorry to hear about the canceled flights