Is Japan still a cash-heavy society?

It is changing rapidly. While major cities and tourist spots accept cards everywhere, small local shops and rural shrines often only take cash. Carry at least 20,000 JPY in cash at all times.

What is DCC (Dynamic Currency Conversion)?

It is a service offered by merchants that allows you to see the charge in your home currency. It is almost always a trap designed to charge you an extra hidden fee for the 'convenience' of not having to do the mental math.

How to avoid foreign transaction fees in Japan

Avoid foreign transaction fees by using a debit or credit card that explicitly waives them and by always choosing to pay in Japanese Yen (JPY) at checkout. Never select 'USD' or your home currency on a credit card terminal, as this triggers a dynamic currency conversion (DCC) fee.

Check your cards before you leave. Log into your bank’s website or check your credit card benefits page. Look for 'Foreign Transaction Fees.' If it says 3%, you need to apply for a 'no foreign transaction fee' card (like a travel-specific Visa or Mastercard) at least 3 weeks before your flight.
Always pay in JPY. When paying at a restaurant, hotel, or shop, the terminal may ask if you want to pay in your home currency or JPY. Always choose JPY. Choosing your home currency forces the terminal to use its own predatory exchange rate, which is often 5-10% worse than the market rate.
Use 7-Eleven ATMs for cash. While your bank might charge a flat fee for international withdrawals, 7-Eleven (Seven Bank) ATMs are the most reliable. Avoid currency exchange booths at the airport; their spreads are significantly higher than bank rates.
Notify your bank. Most modern banks no longer require travel alerts, but it’s still worth checking your mobile app to set a travel notice to prevent your card from being locked due to 'suspicious' international activity.

Is Japan still a cash-heavy society?: It is changing rapidly. While major cities and tourist spots accept cards everywhere, small local shops and rural shrines often only take cash. Carry at least 20,000 JPY in cash at all times.
What is DCC (Dynamic Currency Conversion)?: It is a service offered by merchants that allows you to see the charge in your home currency. It is almost always a trap designed to charge you an extra hidden fee for the 'convenience' of not having to do the mental math.