Can I buy iPhone Japan model by us credit card

Yes. That will work. As mentioned, if your US issued credit card works internationally (contact the bank to confirm) then it can be used to make purchases anywhere in the world. It is not up to Apple to control that. It is up to the issuing bank.

Axel F.

If you are able to use your U S issued credit card in Japan, then you should be able to make a purchase on a Japan based website from Japan.

Axel F.