Check first
At the border
🛂 ENTERINGJapan 
Allowed - but you must declare large sums.
- Carrying cash is legal, but amounts over the threshold must be declared.
- Typical limits: US $10,000 / EU EUR 10,000 (or equivalent).
- Not declaring can mean seizure and fines.
Helpful sources
🌐Japan Customs — passenger clearanceOfficial guidance↗To be 100% sure, we always recommend confirming with the official channels.
Import rules change often and vary by nationality. Confirm with the Japan customs authority or your embassy before you travel.