I bought a iTunes gift card from japan. My App Store is us. Can I still redeem it??

If you can‘t redeem your iTunes or Apple Music Gift Card or content code - http://support.apple.com/HT201195

Card or code is from a different country or region

App Store & iTunes Gift Cards and Apple Music Gift Cards are specific to your country or region. If you're trying to redeem an App Store & iTunes Gift Card or Apple Music Gift Card that was purchased in a different country or region, make sure that you're redeeming it in the iTunes Store for the same country or region. You can't redeem cards outside of the country or region of purchase.

No. iTunes Store gift cards can only be redeemed or spent in the country of origin.

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