Operators of conveyor belt sushi chains, already hit by higher costs for ingredients and lingering COVID-19 concerns, are now dealing with a new problem: the disgusting antics of some of their customers.

The companies fear the images from a flurry of online videos showing such unruly and unhygienic behavior will turn away regular and possibly new customers.

The chains could bring in more workers to keep a lookout for such inappropriate action, but that could require a further spike in food prices to cover the higher personnel costs.

At least one chain said it will take legal action against such offenders.

Akindo Sushiro Co., operator of the Sushiro chain, released a statement on Feb. 1 saying it will pursue criminal and civil cases against customers who commit inappropriate acts at its restaurants.

The statement followed a video that spread on social media showing a young male customer at a Sushiro outlet in Gifu licking the rims of unused teacups and the spout of a soy sauce bottle.

The operator filed a complaint with local police on Jan. 31 after cleaning all the teacups and replacing all soy sauce bottles at the outlet.

Hama-Sushi Co., which runs the Hama-Sushi chain, also suffered financially when a video circulated on social media of a customer putting wasabi in sushi on a plate that was still going around the belt.

Chains generally do not put wasabi in their sushi. Customers, including children, decide at their tables whether to use the spicy substance.

In another video, a man takes a plate off the conveyor belt, lifts up the plastic protective covering, appears to do something to the food, and then places the plate back on the belt.

This occurred at a Kura Sushi shop, which is operated by Kura Sushi Inc.

The video is believed to have been shot about four years ago, but it was recirculated with the recent hashtag #sushi-terror.

The image of conveyor belt sushi chains had previously been hurt by footage of part-time workers performing malicious pranks with the food.

That practice was called “part-time job terror” on social media.

Now, the operators must respond to “customer terror.”

The companies were already struggling with the surge in import prices of food items amid strained global supply chains stemming from the coronavirus pandemic, the war in Ukraine and a weaker yen.

To weather the crisis, the top two industry players--Akindo Sushiro and Kura Sushi--raised the prices of their cheapest offerings last fall.

That resulted in a drop in customers.

The decline was particularly tough for the Sushiro chain. It was still trying to recover from a scandal over an advertising campaign for limited-time items, which were never available at some of its restaurants.

Even a slight dip in customer numbers can have a significant impact on the balance sheets of sushi chain operators, according to Nobuo Yonekawa, an expert on the conveyor belt sushi industry.

“A fall of 0.1 percent in customers would translate into a loss of about 100 million yen ($756,000),” he said. “It requires time and money to implement measures that can deter harmful pranks. They will keep losing money until the deterrence effect is put in place.”

To counter labor shortages and to reduce personnel expenses, large chains have introduced touch panels that customer can use to order from their tables and counters. Self-checkout terminals have also been set up.

Customers can effectively dine without interacting with a shop employee.

The move was seen as positive step to reduce possible exposure to the novel coronavirus from strangers, including workers.

But Yonekawa pointed out that fewer shop workers meant that the unruly behavior of customers would more likely go unnoticed.

“It unwittingly created an environment in which some people were tempted to shoot videos of their pranks,” he said.

However, hiring more workers appears out of the question.

As a temporary countermeasure against boorish behavior, the Sushiro chain has decided to limit items on conveyor belts to those specifically ordered by customers.

It is also setting up transparent panels between the conveyor belts and customers’ tables at more than 600 outlets across the country.

The Kura Sushi chain will renovate its AI camera system so that it alerts shop workers when it detects a customer returning an item to the conveyor belt.

Other fast food restaurants are moving to guard against potential pranksters.

Ichibanya Co., which runs the Curry House CocoIchibanya chain, now sets a bowl of sweet and salty sliced vegetable pickles on a table only after a guest is seated. Previously, every table, even empty ones, had such bowls.

The company shifted its practice after a video spread about three years ago showing a customer eating the pickles directly from the spoon for the bowl, rather than adding the condiments to a plate of curry and rice.

An official of a chain of buffet restaurants said the hospitality industry needs to rethink the way it operates because some customers are now behaving in a manner unthinkable in the past.

The chain uses surveillance cameras while employees made the rounds to check for any irregularity at its restaurants.

It is now consulting with lawyers on potential measures it can adopt as a deterrence.

(This article was written by Tomohiko Kaneko and Kazumi Tako.)