Originally Posted by oneworld lounge access rules
First and Business Class customers connecting on the same day of travel, or before 6am the following day, can access the lounge when travelling between an international long haul* and an international short haul or domestic flight (and vice-versa). (* a oneworld international long haul flight is defined as an international flight marketed and operated by any oneworld carrier with a scheduled flight time longer than 5 hours)
This is the relevant excerpt, found here.
http://www.oneworld.com/ffp/lounge-access
Since your flight to NRT is a redeye it really should qualify but on paper you're not connecting "on the same day of travel". Either way I'd go in armed with this printout and with the mindset that you're not taking no for an answer.