So has Air Japan been on a constant hiring cycle, you can't judge these gigs for that reason alone. There is a simple fact about all these expat gigs and it is the fact that there are no better options back home for us because of age, marital status, economic reasons and so forth, all these expat gigs fill a gap, they are not ideal by far nor this was the career we envisioned for ourselves when we started flying!
Both Korean and Air Japan have the best commuting conditions of any other expat gig out there so for people that want to escape the sandbox or are tired of the ridiculous nonsense that is China, then they become a choice but only as default and certainly NOT because they are your ideal choice for a retirement job; Both of them come plagued with cultural implications that can be from annoying to just plain stupid, and in both cases the local pilots believe that it is good airmanship, they are convinced of that and if you don't conform that will make your life in those two companies very hard indeed!
Do people make it work? Sure, I've been at Air Japan for 13 years but if there was a chance back home, even for a lot less money, I wouldn't put up with the ridiculous stupidity that is training in Asia!
It might work for you until it doesn't, it is that simple! And it doesn't matter one bit if it is contract or direct employment, you work for them until it no longer works for them, they have many ways to make it unbearable enough for you that you will do the dirty work for them and leave!