Japanese cell phone giant NTT DoCoMo has expanded services available to its customers from Japan traveling in Hawai'i.

Takeshi Nakajima, who works in the company's Waikiki office, said the new service allows NTT DoCoMo customers to use their cell phones to show retailers e-coupons that can be used to receive discounts at hotels, restaurants, stores and other businesses.

Nakajima said more Japanese travelers are using their cell phones in Hawai'i as the technology improves and rates decline. New multi-band cell phones will work in both Japan and the United States, which have different cellular systems.

NTT DoCoMo, which launched the new service Tuesday, opened its shop in Waikiki three years ago, Nakajima said.

Nakajima said the new discount gives customers a chance to get a discount with the cellphone they are carrying anyway rather than having to carry paper coupons that they pick up in magazines or brochures.

He said the service has been successful in other vacation destinations such as China, Guam and Saipan.

NTT DoCoMo is Japan's largest mobile communications company, with 53 million subscribers, 46 million of whom are premier club members, he said. "We're expanding membership in Hawai'i."

Nakajima said the average number of NTT DoCoMo customers using their phones in Hawai'i on any given day is about 37,000.

Nakajima said travelers will still pay higher prices to make local calls even with international roaming service, so he said that's why most travelers opt for calling Japan or e-mailing while they are here. Sending e-mails also helps customers avoid any inconvenience caused by the 19-hour time lag.

But he said his company offers a better price than its competitors. "We believe it's the cheapest if you're making a call to Japan and receiving a call from Japan."

And service has come a long way from a few years ago when Japanese visitors couldn't bring their phone and use their own number while they were traveling because of technology differences.