Discussion on question by Santhosh Sundar: Can we carry rice to Japan?

@KonradRudolph As a 40-year-old native speaker of English, I have literally never heard this proverb so I dispute your claim that it's at all common in English. I also doubt that the link would be obvious to most people who don't know the proverb: for example, the only occurence of the word "owl" in the Wikipedia page on Athens is an external link to "Athenian owl coins" right at the end.

I would say SE rules apply; you're expected to show what effort you have made on the problem. When you have a problem with an obvious, easy solution, you need to show why the easy solution won't work for you.

@SanthoshSundar: I read Janka's comment as a (valid) question for clarification (although phrased in a humorous way): Why would you want to bring something that is readily available in Japan to Japan? You are right, we do not understand the circumstances, so please explain them to us. :-) Giving a bit of background is encouraged to avoid XY problems.

Re:Cheaper - you are aware that 10kg of air luggage is quite expensive? You're either going to take very few clothes for 18 days, or wind up paying lots extra to cover the cost of flying it.