A Japanese sushi chain targeted in a spate of pranks that has sparked concern over hygiene has devised a digital conveyor belt to serve food to customers.

Instead of placing sushi on a rotating conveyor belt for customers to pick up — famously known as "kaiten" style — three stores will replicate the experience through animation played on a touchscreen fitted to every table, Akindo Sushiro Co., which runs the Sushiro chain, said in a recent statement.

Customers can order by tapping on screens showing cartoon sushi and other food. The sushi will then be delivered directly to their table on a separate conveyor belt from the kitchen.

The company said it began piloting the "next-generation shop experience" on Tuesday at three stores in Tokyo, Osaka and Nagoya.

The chain had been subject to a string of pranks dubbed "sushi terrorism" since the start of the year.

Inspired by viral online videos, pranksters filmed themselves licking shared soy sauce bottles or tampering with food rotating on conveyor belts at the chain's restaurants.

Police have arrested at least five people in two separate cases involving pranks at a sushi restaurant and beef bowl chain so far this year.

In June, public broadcaster NHK reported that Akindo Sushiro was suing a high school student for 67 million yen ($480,000) after social media footage uploaded in January showed him licking his finger before touching a plate of sushi as it passed him on the conveyor belt.

The company claims to have lost about 16 billion yen ($115 million) following the release of the video showing his actions at a Sushiro outlet in the central city of Gifu, which it said caused a sharp drop in customers and a slump in the stock of its parent company, according to NHK.

A digital experience

Akindo Sushiro said the touchscreens combine a digital experience with the traditional "pleasure of seeing the belts and being able to choose sushi."

"We will evolve while maintaining our commitment to deliciousness," it said in the statement, adding that customers can enjoy their sushi "with peace of mind."

It said the screens can be used by two people at once and diners can also play games and quizzes on the new terminals.

Some customers appreciated the effort to improve hygiene.

"It actually makes sense and is likely to provide more of a modern atmosphere, particularly for tourists approaching Japan after Covid," said Alessio Procopio, an Italian living in Tokyo, adding that it could also help reduce food waste.

But others worried the move could chip away the essence of the traditional kaiten style.

"It will be a pity to lose the sushi train," said Hideki, another frequent patron, who preferred to give only his first name.

The student from western Hyogo prefecture said he would miss the convenience of being able to pick up sushi directly from the conveyor belts, if they are eventually phased out completely.

"If it's just digital, you have to ask for it before the product arrives, so it's less convenient," he said.