NRT is one of the most efficient airport.

One can deplane, clear security, enjoy a few drinks and snacks at Skyclub, then board a US bound flight in less than 90 minutes.

Tip: there are two Skyclubs, one in each pod. Gates in the 20's is one pod and gates in 10's are in another, just go to the pods which are circular shape and there will be an elevator/escalator to take you up to the club.