Thanks all for your input.

I see that in my originator posting I did not note that I was flying on an Alaska Mileage Plan reward ticket.

Now flying in and out of Narita and seeking further clarification. Was lucky to find an award ticket with a date change.

Will be arriving at Narita at 4pm on a first class flight and leaving the next morning at 10:50 flying to Jakarta in coach.

I thought I read somewhere that people arriving on first and departing on a coach flight the same day can use the first class lounge. I was hoping even though my departure is not til the next day that I might get to enjoy dinner at the lounge then get some sleep at the capsule hotel before my morning flight.

I just phoned JAL customer service and was told that as I am flying on an Alaska reward ticket I will not have access to the first class lounge at all.