this is what happened at the Japanese custom check today
(the following conversations in Japanese)
custom officer (looking at my travel document): where are you from?
me: america.
custom officer: ah, you are an internationl student!
me: hai hai.
custom officer: you of course did not bring any of the prohibited items right?
me: hai hai.
and then he let me pass without even opening my cases, let along x-ray it.