According to NTT Docomo, the smartphone payment service "d payment" has become difficult to use on some terminals after 10:00 am on the 19th.
The company is currently investigating the spread of the impact and the cause, as there is no prospect of recovery.
There are more than 45 million users of "d payment", and NTT DoCoMo commented, "We apologize for the inconvenience caused to our customers. Please wait for a while until the service is restored."