Media reports indicate that shops and restaurants in sushi-mad Hong Kong, one of Japan's key food export markets, have been hit badly by the radiation scare.
Well-heeled consumers in the city are normally willing to pay a premium for food imported from Japan, deeming it less likely to be affected by food safety scandals that have rocked mainland China, for example, in recent years.
But with the Chinese territory on Wednesday becoming the first Asian economy to slap an import ban on a variety of Japanese food after radiation was found in vegetables from Japan, consumers were shopping elsewhere.
The ban applies to dairy products, fruit and vegetables from five prefectures near the Fukushima No 1. nuclear plant, which was hit by a powerful quake and tsunami on March 11, followed by a series of explosions and fires.
Supermarkets that are usually popular with Western and Japanese expatriates as well as wealthier local Chinese consumers were markedly less busy Thursday.
Japanese chains APITA and Jusco, as well as Japanese restaurants in the city were all quiet, despite hefty discounts on fruits and vegetables imported before the ban came into effect, with shoppers showing little interest.
"For sure I will avoid buying Japanese products -- like vegetables, mushrooms and fish," Jane Shum, a retiree in her 50s told AFP.
"Even here, businesses are affected a great deal, look, no one is buying Japanese products" she said, gesturing to the relatively empty supermarket.
The upmarket stores, which offer everything from air-freighted sushi lunchboxes to perfectly formed fruit at eye-wateringly high prices, were facing a very swift reversal in fortunes.
Housewife Irene Wong said she would avoid any Japanese food.
"I am definitely choosing food products from places other than Japan," said the 65-year-old, adding "there are plenty of choices out there".
The city's Food and Environmental Hygiene Department ordered the ban Wednesday after vegetable samples arriving from Japan showed traces of radioactive iodine as much as 10 times above recommended levels.
Meat, poultry and seafood imports will also be banned unless first given safety clearance from Japanese officials, the Hong Kong government has said.
A potential ban on fish and seafood will be a particularly harsh blow for restaurants in Hong Kong, a teeming city of seven million.
Fears across the city also sparked calls to implement a wider ban on food imports from Japan, with a lawmaker saying all food imports close to the crippled Fukushima nuclear power plant should be stopped.
"Japan's standards are different from ours -- even if the food imports pass their safety inspection, it doesn't mean the food is really safe," Fred Li, a member of the Food Safety Panel in the city's lawmaking body, told AFP.
According to Li, business for Japanese restaurants and supermarkets have plummeted by up to 40 percent, with sushi outlets suffering the most.
"Businesses are trying to source from places outside of Japan, but the reality is, business will suffer for weeks to come," he said.
Hong Kong imported about HK$5.7 billion ($730 million) worth of food from Japan last year, according to official figures.
Besides Hong Kong, the United States, Australia and Singapore are among leading markets to have banned certain Japanese food imports.
France has urged the European Union to introduce "systematic controls" on Japanese food, while South Korea said it was considering banning food shipments from areas near the quake-damaged plant.