With its masters required to hone their skills over decades, sushi in Japan is steeped in tradition, but it is also often a high-tech operation where robotic precision steals the limelight from the chef’s knife.
The country is dotted with thousands of kaiten (revolving) sushi restaurants where raw fish slices atop rice balls travel on conveyer belts along counters waiting to be picked up by diners.
However, behind the scenes it is far from a simple merry-go-round, with robots in some locations rolling out perfectly-sized rice balls onto plates embedded with microchips.
Measured dollops of spicy wasabi paste are squirted onto the rice assembly-line style before they are topped with raw fish. The most cutting-edge eateries are even connected to monitoring centers that can quickly tell whether the right balance of dishes is being produced — a far cry from traditional places where the sushi chef and his knife still reign supreme.
“Sushi isn’t going round at random, but rather it is coming out based on a number of calculations,” said Akihiro Tsuji, public relations manager at Kura Corp, a major operator in a market expected to post US$5 billion in revenue this year, according to industry figures.
“Though traditional, sushi is stuffed with high technology. You can’t operate low-price revolving sushi restaurants without databases and scientific management,” he said at a Tokyo outlet.
Kura has invented a serving device called sendo-kun, which translates roughly as “Mr Fresh,” a plate with a transparent dome that opens automatically when diners select the dish.
While the hood keeps the sushi moist and clean, it also contains a microchip telling managers what kinds of fish are going around on the conveyer belts and how long they have been there.
Since their birth half-a-century ago, kaiten sushi restaurants have evolved from selling traditional sushi into miniature museums of the food that Japanese people eat today, including battered tempura, noodles and even ice cream. The dishes are cheap, usually starting at about ￥100 (US$1) for two pieces of sushi.
Now, more and more outlets are equipped with dedicated “high-speed” lanes where customers can make their order via a touchscreen menu.
Ryozo Aida, a 68-year-old university lecturer, said he visits Kura outlets with his wife because of its “affordable prices.”
“It may sound strange in a sushi restaurant, but I like tempura,” he said as he jabbed his fingers at a touchscreen panel.
Inside the kitchen, screens show how many adults and children are dining and approximately how long they have been in the restaurant.
“Even if all the 199 seats here are occupied, how much sushi we need will differ depending on how long they have been at the table,” Tsuji said.
The system combines real-time data with information about how many items were consumed in similar circumstances in the past, displaying results for kitchen staff.
Complementing on-the-spot efforts, the Kura chain also has a remote assistance system serving its network of more than 300 outlets.
In-store cameras feed images to dozens of supervisors who move from restaurant to restaurant with laptops, while others watch from monitoring centers to advise restaurants instantly if there is enough food and the right mix of offerings on the conveyer belt.
The cameras can zoom in on sushi to make sure it is laid out in regulation elegance, although they do not monitor customers’ faces for privacy reasons.