I have been through he selection process. It involves a sim ride ( if you've been passing your checks up to now you won't have a problem) a rather short and bizarre interview (they don't speak much English - so keep respectful. positive and speak absolute rubbish) and a very thorough medical (if you've been passing medicals up to now you won't have a problem.
You fail - they let you know. (After a while)
More likely - You pass. You wait and wait and wait. Some go straight to Japan but the majority enter a sort of limbo hold pool. If you piss off the Japs with the most trivial thing you will probably remain in the hold pool forever (along with hundreds of others)
Don't buy a Japanese phrase book quite yet!