I have upgraded the LAX-HKG-LAX segments from J to F on LAX-HKG-MNL-HKG-LAX many times. If available you can confirm it online or place yourself on the waiting list. You can also upgrade at the departing Airport at check in if available. usually 1 to 2 hours before departure. I have upgraded the segment at LAX and at HKG.
My Destination is MNL via HKG one ticket. I can't imagine Haneda is any different
Currently 75,000 Asia miles each way.