Japanese-issued credit cards can be used to make calls from more than 40 overseas regions to other countries outside of Japan or to make domestic calls within foreign countries.
¡üWe will terminate credit calls at 11:59 a.m. Japan time on February 28th, 2019.
The rate for a call from country X to country Y is equal to 60% of the rate for a call from country X to Japan plus 60% of the rate for a call from Japan to country Y. (All rates are rounded down to the nearest yen.)
You can use your credit card to call Japan from overseas.
KDDI International Phone Service Lineup List