Cards bought in Japan can only be used on accounts registered to the Japanese region.
Buying Japanese iTunes (Apple) gift cards is the standard way for users outside of Japan to access the Japanese App Store, as foreign credit cards are generally not accepted there. These cards allow you to purchase Japan-exclusive games, music, and media. buy jp itunes cards
Digital codes are usually sent via email within minutes of purchase from reputable online retailers. Where to Buy Safely Cards bought in Japan can only be used