In answer to your question, JAL pay consists of many components.
Basic pay per month- £595 (£535 during probation)
Unsocial hours- £132
LHR weighting- £128
Payments for working Sat/ Sun- each £30
Bank Holiday/ Xmas/ New year- £60
Flight pay:
LHR/ AMS/ CDG/ MXP/ FCO- JPN- £112
JPN- LHR/ FCO/ MXP- £112
JPN- AMS/ CDG- £131
Oh, and hotel expenses (or what we call "per diem".
Not bad eh, and good luck if you are applying.
I have been at JAL for nearly 7 years now and still enjoy it. The destinations may not be "WOW", but we have great crew flying for us and we do enjoy ourselves. See you at the truck!!