Well, I came to Japan as a NTR, DEC...., it is a different training philosophy for sure but not that difficult quite frankly, It is a matter of adjusting yourself to be an actor on a play, people tend to try to perfect the movements and facial expressions when they should be concentrating in knowing the script by heart.
Pretty much the same thing as to why folks get in trouble during training, they want to fly the SIM within 10 feet and be on speed within 5 knots on the second SIM when they should be concentrating at your fullest on the SOP's and calls, if you blow the altitude by 100 feet but they see that you are making an effort into getting all your calls and SOP's just right, they are not worried about you not flying the SIM to precision because they are going to give you tonnes of SIM sessions to get your flying correct, but if by SIM 3-4 you are not getting those calls and procedures correctly, it doesn't matter that you fly the SIM better than the A/P, what they are thinking is not "Wow, he does fly the SIM well" what they are thinking is, "Hum, he is having difficulty with our way"
That is mostly the biggest issue people have, the other one is attitude, If you are the type that is constantly pointing out the way you did it at brand X and asking Why is it done that way here, Japan is not for you.