Every passenger declares on a customs declaration form, and which channel you walk through depends on what you carry.
Which channel
- Green channel: you have no goods subject to duty, tax or restriction.
- Red channel: you do. Duty and tax are paid at the bank inside the customs inspection zone, not at the counter.
Unaccompanied baggage
If you have unaccompanied baggage, submit the declaration form in duplicate when you enter, not once. The second copy lets your delayed or shipped baggage clear later.
Banned without a permit
Hunting guns, air guns and swords cannot come into Japan without a possession permit.
Allowances
Japan publishes duty-free and tax-free allowances for alcohol, tobacco and perfume, and a declaration threshold for cash and precious metals. The figures are in a table on the official page linked below.
The source gives no comparison with other countries. Japan is at the generous end of the region, while Hong Kong allows nineteen cigarettes, a gap of more than ten to one. How Japan’s allowance compares across the region sets them side by side.