Koyo USA Corp. is opening a showroom in Waikiki Monday to elucidate and sell its bottled MaHaLo Hawaii Deep Sea drinking water.

Prices for the water at Koyo's Waikiki showroom will be about twice as much as typical bottled water. A half-liter bottle retails for $2, with a 1.5-liter bottle going for $4.50. In Japan, Koyo sells its 1.5-liter bottle for $6.

The roughly 1,200-square-foot showroom on Seaside Avenue in the Waikiki Shopping Plaza is described as part museum and part store, with displays describing the evolution of the product from Hawai'i, and a bar selling and serving bottles, coffee and tea containing the desalinated seawater.

"It's like a mini museum," said Yutaka Ishiyama, marketing and sales manager for Koyo. "It's like a water museum to explain our deep seawater."

Some of the products in Japan have been marketed as a dietary supplement that improves weight, stress, skin tone, digestion and has other health benefits yet to be proven via scientific study.

Labels on Koyo's water in Hawai'i don't make health claims but tout it as being thousands of years old, filled with minerals and free of modern impurities. The water is largely desalinated, leaving a tiny bit of sodium to give it a somewhat discernable taste.

Ishiyama said the primary purpose of the Waikiki showroom is to expose consumers to the water, which is well-known in Japan, where Koyo sends about 300,000 bottles a day, but is less known in Hawai'i or the Mainland because until recently the company could not sell its product in the United States.

Koyo recently obtained state Health Department approval to sell its seawater in Hawai'i, and last month began selling MaHaLo at the Neiman Marcus store in Ala Moana Center.

Lucy Chelini, a spokeswoman for Neiman Marcus, said Koyo's water has drawn curious interest from shoppers, some of whom aren't sure what the product will taste like.

"They are fascinated about it," she said. "They want to know more."

Chelini described the desalinated seawater as having a different texture than tap or spring water. "It has a smoothness," she said. "It's not salty."

Koyo's Waikiki showroom will be the second retail outlet for the company outside Japan.

"This is just a start," Ishiyama said, adding that he would like to add more U.S. retail outlets and possibly a second showroom on the Mainland. Ishiyama said he also expects other local deep-seawater producers to join Koyo selling bottled water in Hawai'i and Mainland markets.

The industry surfaced in Hawai'i several years ago at the Natural Energy Laboratory of Hawai'i Authority business park off the Big Island's Kona Coast, where pipes deliver cold, nutrient-rich water from 3,000 feet deep.

Deep SeaWater International Inc. also bottles seawater at the site, and several other companies plan operations there, including Enzamin USA Inc., Hawaii Deep Marine Inc. and Savers Holdings Ltd. Another company, Deep Sea Health LLC, plans to pump deep seawater into a boat off O'ahu.

Reach Andrew Gomes at agomes@honoluluadvertiser.com.