Japanese police have arrested three people over viral, unhygienic pranks labelled as "sushi terrorism" - actions that have threatened the reputation of world-famous sushi conveyor belt restaurants.
A video of a man licking a soy sauce bottle and squashing dishes on a sushi conveyor went viral last month, sparking outrage online.
Since then, several videos of similar, unsanitary pranks have made the rounds, stirring up health and safety concerns for conveyor belt sushi restaurants, known as kaitenzuishi in Japan.
The "sushi terror" attempts have included diners rubbing saliva on pieces of sushi, adding wasabi to dishes and licking chopsticks as they pass by.
In eastern Japan, the Choushimaru chain said it would stop using its conveyor belts altogether after a customer placed a cigarette butt in a jar of pickled ginger.
Police in the central Japanese city of Nagoya allege Ryoga Yoshino, 21, licked a communal soy sauce bottle at a Kura Sushi conveyor-belt sushi restaurant on February 3.
Two minors aged 19 and 15 were also involved, police saying their actions constituted obstruction of business under Japan's Penal Code.
All suspects admitted to the wrongdoing, police said, one reportedly apologising for his actions.
The viral trend has horrified diners in Japan, a country renowned for its high standards of cleanliness and culinary etiquette.
One woman, Yukari Tanaka, told the BBC that: "I know people from overseas look forward to eating sushi here so as a Japanese person, I am ashamed of such actions".
Another person, Nana Kozaki, said: "Kaitenzushi is Japanese culture we can be proud of but actions of few people like that really ruins that".
Others Japanese locals say they have been scared by the trend and have since become more reluctant to visit restaurants.
A spokesman for the Kura Sushi - the restaurant chain targeted by those arrested - told the BBC that the viral video trend was "extremely dangerous" and posing a threat to the foundation of the conveyor-belt restaurant model.
"Conveyor belt sushi is something we are proud of as part of Japanese culture. We want to make sure our customers can eat sushi delivered on the belt safely and comfortably," he said.
The trend has forced restaurants around Japan to alter practices to reassure customers of their hygiene standards.
Kura Sushi has now developed an alert system, where some conveyor belts are now equipped with sensors and cameras that detect interference with plates.
The company said the sensors would also be able to identify the specific plate and seat number involved.