
Pretty much every other card I've looked at gives you rewards in some kind of points and while most points can be used for purchases, those purchases are limited to places where those points can be redeemed. So comparing which card gives you the better deal is tough given that a lot seems to depend on your shopping habits and where you shop. If you did the majority of your shopping via Rakuten or say Amazon, there are cards tailored to those platforms. It's unclear to me which cards are best suited to those who are not married to a single platform. We do have a Saison International Visa card which has no annual fee (another requirement for us) but its rewards are points. Granted those points can be redeemed for certain things but it still isn't as nice as just getting straight cash back that can be used to pay for anything your heart desires.
We have a U.S. based cash back card (via USAA) that we should be able to continue using in Japan but it's unclear whether we will have any issues using that card for things like utility payments where we may have to input a billing address. Our plan would be to use the same card for utilities (electric, gas, water, internet, keitai, etc.) as well as groceries. If the majority of our monthly expenses can be paid by the same card that seems like the best way to maximize our rewards.