From Qatar:
- Take some USD; QAR is rarely exchanged in Japan, especially outside big centres.
- Many small shops and some landlords only take cash, so don’t rely solely on cards.

Card vs exchange:
- QNB card rates were better than most Qatar exchanges (around 38–39 yen per QAR vs ~32 at many exchanges; Alfardan ~37).
- Use your QNB card in big malls and proper shops.

In Japan:
- Use Seven Eleven ATMs to withdraw yen; they usually don’t charge a local ATM fee (your Qatari bank may still charge).

Strategy:
- Carry some USD to exchange.
- Use QNB card for larger purchases.
- Withdraw cash from 7‑Eleven ATMs as needed.