Daniel Bucheli, a sales manager from Switzerland, booked a spot at the workshop at an Iwasaki-run shop in the Kappabashi area of Asakusa, a traditional downtown area of Tokyo, ahead of his five-week vacation in Japan in the fall.

"I wanted to try a cultural experience we can have only in Japan. Oishiso! ("Looks delicious" in Japanese)," he said as he playfully pretended to bite into the pumpkin tempura he made.

Sam Li, part of a separate group of 15 from Hong Kong, had his first try of food replica making. "I sent my 14-year-old daughter a photo and she said she definitely wants to try. I will bring her here for sure the next time we visit," he said.

Every day, a factory in Yokohama, operated by Iwasaki group company Iwasaki Co., is bustling with 50 or so workers painstakingly crafting food replicas. The production process starts after real food is delivered in bowls or plates actually used in eateries.

The craftsmen first take a mold of each ingredient. After plastic resin is poured into the mold and heated in the oven, the basic parts are ready for coloring.

Artisans use airbrushes, mixing various colors, drawing the fine marbling lines on sashimi or small dots on the skin of pears made to look exactly like real ones.

The craftsmen traditionally spend three years taking molds and getting the feel of the different colors and textures of the ingredients before learning the coloring process.

The colored parts are then arranged together on the plate or bowl provided by the restaurant, followed by the finishing touches, such as pouring sauce or polishing.

"The goal is to make them look so real that you can practically smell them," said Hiroaki Miyazawa, manager of the factory who has been making food replicas for 28 years. "The most difficult parts to recreate are raw ingredients like fish and herbal leaves."

In response to the decreased demand from eateries, which account for the bulk of its revenue, Iwasaki has been exploring other potential markets.

Focusing on the Japanese agricultural industry's labor shortage, it is developing replicas of crops such as vegetables and fruits for use in teaching unskilled or temporary foreign workers.

There is also demand from pharmaceutical companies for replicas of medicines.

Production of food replicas has also evolved, with materials used to make food samples changing from wax to synthetic resin around the 1980s to tackle the issue of durability, since wax tends to melt or degrade under heat and sunlight, especially when placed near windows of restaurants.

Iwasaki has also been moving to use environmentally friendly materials, starting with 10 percent biomass-based ingredients, to address concerns from consumers abroad.

In London, an exhibition introducing the unique history, culture and craftsmanship of food replicas opened in October. Visitors saw some 150 replicas of Japanese delicacies, including one from each of the country's 47 prefectures, made by the Iwasaki Group.

The feedback was positive and traffic on Iwasaki's website from Britain has quadrupled.

"It's amazing how things like this can start as a marketing device and become an art form in their own right," said Matilda Davies, a British visitor to the exhibition.