A Japanese restaurant that has helped the naval port city of Yokosuka establish its reputation as a "curry town" is in its final summer of operation.

The restaurant, Gyorantei, says it has decided to close after serving its famous Navy Curry for the last time on Aug. 31, citing the heavy cost it would incur to renovate its aging curry annex.

The curry became a hit after the restaurant, in cooperation with neighboring competitors, reproduced its recipe from the one given to the Japanese Imperial Navy by the British Royal Navy in 1908.

The success soon led the local chamber of commerce to certify Gyorantei in 1999 as the first to serve Navy Curry in the city, looking to make it a major tourist draw.

The annex opened shortly afterward and the number of certified curry shops and restaurants has now grown to 42, helping to prop up tourism in the Kanagawa Prefecture city that houses a strategically important base for the U.S. Navy and Japan's Self-Defense Forces.

Former Prime Minister Junichiro Koizumi was once among Gyorantei's regular clientele. The restaurant will close on July 30, one month before the annex's scheduled shutdown.

"It's regrettable but it's impossible to keep our business going," said Hideki Kurita, a chef who was a potential successor to his uncle and former owner who died in April.

Curry made with the same recipe will continue to be sold in pouches at some local stores even after the famous business shutters.

"We'll keep alive this recipe, which is a treasure for us, and I want to run a restaurant again sometime, somewhere," Kurita said.