On Sunday afternoon in the Dai Nagoya Building in Nagoya, Japan’s industrial capital and one of the centers of the novel coronavirus outbreak in the country, Tully’s Coffee is shuttered. A small sign outside the entrance says that, due to Covid-19, the rooftop cafe will be temporarily closed.

Every single other store in the mall is open — and bustling.

The mall is a microcosm of the nation’s response to the virus. Some public schools are set to reopen over the next few weeks, just over a month after Prime Minister Abe Shinzo shut them down on February 27.

The spring university semester begins in early April throughout the country and colleges are proceeding with many classes and orientations, despite canceled graduation and induction ceremonies. Some popular tourist attractions, including Universal Studios Japan, are scheduled to reopen before the end of the month.

Yukino Ichikawa, a college student, said that the main impact of the coronavirus on her life so far has been having a tour she’d reserved getting canceled and improved hand-washing diligence. Others I spoke to had similar experiences. “I may lose my company bonus and I can’t travel,” said Erika Imaeda, a company employee. “I’ve also started to wear a mask to work.”

The country’s reserved approach to tackling the coronavirus has faced scrutiny and speculation about under-testing. Despite taking only moderate social-distancing measures (the government recently asked people to “refrain” from getting together in big groups for cherry-blossom viewing parties), Japan has faced a surprisingly linear growth in cases — that is, until cases suddenly started accelerating in Tokyo earlier this week.

There are nearly 1,400 confirmed cases and over 44 deaths as of March 27. On March 5, 55 new cases were reported. Almost three weeks later, on March 25, just 98 new cases were reported.

Compare that to the US, where 66 newly confirmed cases on March 5 turned into nearly 14,000 new cases on March 25. While much of the world’s new case graphs look like terrifying exponential growth, Japan’s appears to be mainly linear.

But experts say the true number of cases in the country almost certainly exceeds 1,400. The government has been criticized for its strict testing criteria, which requires patients to have had a fever of greater than 37.5 Celsius (99.5 F) for more than four days, unless the patients are elderly, have other underlying health conditions, or are connected to a previously confirmed case. Some people who meet the criteria have been denied tests.

Even the United States’ badly flawed and belated testing effort eclipses Japan’s minuscule effort — as of March 20, the US had conducted 313 tests per million people compared to Japan’s 118 tests per million people. Japan is using just 15 percent of its supposed testing capacity of 7,500 tests per day. South Korea, widely praised for its drive-through testing measures, is conducting more than 6,000 tests per million people.

The Japanese National Institute of Infectious Diseases has argued that the strict testing criteria are in place to preserve limited medical resources for those in need of urgent care. “Just because you have capacity, it doesn’t mean that we need to use that capacity fully,” health ministry official Yasuyuki Sahara told the press in a briefing last week. “It isn’t necessary to carry out tests on people who are simply worried.”

Abe’s government is going directly against the WHO’s firm recommendation to “test, test, test,” leading many to conclude that the coronavirus may be far more widespread in Japan than the numbers indicate.

Prime Minister Abe Shinzo answers questions during an upper house budget committee session at parliament in Tokyo on March 27, 2020.

Kazuhiro Nogi/AFP via Getty Images

Now, a growing coronavirus outbreak in Tokyo is threatening Japan’s status quo as 40 new cases in Tokyo alone were confirmed on March 25. While the government has been able to identify the infection route of most of the cases, it’s a worrying sign that life was relatively normal in Tokyo, with muted but still considerable cherry-blossom viewing parties, just a few days before this sudden jump.

Thus far, Japan has managed to escape exponential growth, but the worst may be yet to come. “This may be the tip of the iceberg,” said John Ioannidis, professor of disease prevention at the Stanford School of Medicine. “If you don’t test, you find no cases and even no deaths.”

Timeline of the coronavirus in Japan and the government’s response

Japan’s first case of Covid-19 was a Chinese national who’d traveled to Wuhan — the city in Hubei province, China, where the virus first emerged — and returned to Japan on January 6; the person tested positive for the virus sometime between January 10 and 15.

Two weeks later, Japan confirmed its first case of an individual who had not traveled to Wuhan, a taxi driver in Tokyo who had recently driven a Wuhan tour group.

One arm of Japan’s coronavirus policy has been to build a firewall against the influx of cases from overseas. On February 3, the government moved to bar the entry of people who had a history of traveling to Hubei province, or Chinese nationals with a Hubei province-issued passport.

A month later, those entry restrictions were expanded to include people from certain regions devastated by the coronavirus in South Korea, Italy, and Iran as well as two-week quarantines for all visitors coming from China and South Korea.

Throughout the month of February, most of Japan’s cases were individuals connected to Wuhan, and the majority of cases were isolated and traced. A government-appointed panel reported on March 9 that 80 percent of the cases identified had not passed on the infection to anyone.

But when case numbers failed to abate through February (232 confirmed cases as of February 28), Abe moved to close all schools and request that community gatherings be suspended. Japan was hit by a wave of closures to tourist attractions, sporting events, concerts, and festivals.

The governor of Hokkaido proclaimed a state of emergency beginning on February 28 and asked the population to stay indoors. For comparison, lockdowns began in Northern Italy on March 8, when more than 7,000 coronavirus cases had already been confirmed.

Based on the recommendation of a panel of bureaucrats and infectious disease experts, the central policy has been to focus on providing medical attention to those who are severely ill in order to prevent the nation’s health care infrastructure from becoming overwhelmed, and to do extensive contact tracing to identify infection clusters. The health ministry and doctors are asking individuals with mild symptoms to stay at home so that they do not pass on the disease.

Commuters make their way to work in Tokyo, Japan, on March 26, 2020.

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Public messages reminding people to wash their hands and hand sanitizer are all over Japan.

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Commuters wait in line at a bus stop in Tokyo, Japan on March 26, 2020.

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But as cases have steadily increased, not much has changed in terms of the government’s policy response since late February. The prime minister’s office announced on March 20 that according to the expert panel’s latest recommendation, they would continue to focus on infection cluster countermeasures and preparing the health care infrastructure to be able to treat the seriously ill in the event of a leap in infections.

While Japan has a strong national health care system and more than four times the number of hospital beds per 1,000 people than the US, a shortage of medical supplies is an ongoing concern. More than 90 percent of medical institutions in Nagasaki prefecture have said they are facing shortages of masks and disinfectant, and hospitals in Hokkaido are providing just one mask per hospital visitor per day to protect their supply.

Rather than enacting widespread private or public closures, as has been prevalent throughout Europe and the US, the government’s panel of experts simply asked people to “continue to avoid environments that simultaneously meet the following three conditions: poor ventilation, dense crowds, and dense conversation.”

Many in Japan did not comply with this request. Just this past Sunday, more than 6,500 people gathered for a martial arts event in Saitama, a city just north of Tokyo, despite the Saitama governor’s pleas that the event be shut down. One attendee later came down with a fever and is currently awaiting the results of a coronavirus test.

Better hand-washing, a government conspiracy, or both?

There has been plenty of speculation about the reasons behind Japan’s lack of exponential case growth. Suggestions, both optimistic and pessimistic, have covered everything from the fact that people in Japan don’t typically shake each others’ hands in greeting to the possibility that the government is failing to test tens of thousands of pneumonia patients for the coronavirus.

Here’s an overview of the major factors at play — and what the numbers and experts say about their impact on “flattening the curve” in Japan.

Moderate social distancing was effective because it happened early

Social distancing in Japan is currently a mixed bag. Rush-hour traffic on Tokyo subways is down just 10 percent compared to mid-January. Street traffic in Tokyo has barely budged from its historical average.

A survey conducted by the Osaka Chamber of Commerce and Industry on March 12 showed that 55 percent of large corporations have implemented remote working procedures, but a strict working culture has kept even white-collar workers in the office. Movie theater revenue for March is down around 50 percent across the country.

But even this modest social distancing seems to have had an impact. Sato Akihiro, a data analysis expert and professor of neuroscience at Yokohama City University, calculated that Japan’s nationwide event cancellations and social distancing measures beginning at the end of February have cut the infection rate to 50 percent of what it would’ve been otherwise.

He said that in order to stop the virus completely, the country needs to increase its testing capacity by sixfold to adequately identify and track cases. “We saw event cancellations in Japan from a very early stage,” Sato told me. “I think that cases in Japan are not growing at an exponential rate as a result of these early interventions to reduce human contact.”

Cluster identification and contact tracing

As Sato points out, the key to Japan’s linear rate of infections may stem not from acting more aggressively, but simply earlier, before sustained community spread took root.

Japan began testing individuals with coronavirus symptoms — and not only those with a history of travel to Hubei province — at the discretion of local governments around February 12. The government then created a specialized team of public health and medical experts to identify and isolate infection clusters.

Whenever a hospital confirms a new case, the government dispatches teams of medical and data experts to cooperate with local governments to locate and test anyone who has been in contact with the infected individual. Oftentimes as a result, the corresponding local facilities are closed down, such as a senior care facility in Aichi prefecture that was associated with an infection cluster.

A lack of large case explosions, such as what happened with South Korea’s “Patient 31,” who singlehandedly spread the disease to thousands, suggests that these cluster countermeasures have been mostly effective thus far.

Sanitation and mask-wearing are real factors

While it’s more likely that Japan’s early cluster tracking and social distancing measures are the main factors in limiting an explosive spread of the virus, famously clean Japan does have difficult conditions for a virus to thrive in.

While good hygiene is far from universal in Japan, many people practice frequent hand-washing, gargling, and disinfection. Japanese people rarely shake hands, hug, or kiss when greeting — a key chance for the virus to spread.

A notice displayed in a park during cherry blossom season informs people about coughing manners in Tokyo.

Carl Court/Getty Images

For reference, a 2015 survey found that 15 percent of Japanese did not wash their hands after using the toilet, compared to 40 percent of Americans. Hand-washing reduces the risk of respiratory infection by 16 percent, according to the CDC.

In terms of surgical and N95 masks, a Weather News survey from January 2018 revealed that 53 percent of Japanese people wore masks regularly — a number that has almost certainly increased this year with the alarm bells about coronavirus. A 2017 scientific study found that mask-wearing reduced risk of influenza among Japanese schoolchildren by 8 percent.

“Personal hygiene and social responsibilities are main pillars for disease prevention practice,” HyunJung Kim, a PhD student in biodefense at George Mason University, told me. “However, it is [irresponsible] to assume that 100 percent of the population of a country will have the highest level of hygiene and social responsibility. Outliers always exist.”

Other theories

Japan may have other factors on its side, as well. Mitsuyoshi Urashima, a practicing pediatrician and professor of medicine at Jikei University, suggested that the coronavirus was spreading in Japan in mid-January, at the height of the flu season, whereas the virus did not spread in the US and Europe until after the flu season’s peak.

“[My view is that] the outbreaks were ‘batting’ against each other in Japan, reducing the prevalence of both diseases,” Urashima said.

Japan also has an accessible, inexpensive, and widespread national health system that is excellent at treating pneumonia, the main way that coronavirus kills. Edo Saito, owner of a Japanese/multinational executive consulting agency, points out that from the age of 65, all citizens are enrolled in senior care services programs, which include home pickup to senior day care centers and having doctors and nurses call in on homes.

These expansive and accessible health care options may be providing an additional safety net for Japan’s large elderly population. Japan’s elderly population is also uniquely (and tragically) isolated, which may reduce contact with asymptomatic virus-carriers.

Some speculation around Japan’s low coronavirus numbers suggested that the government was repressing the extent of the infection to ensure that the 2020 Tokyo Olympic Games would be held on schedule. With the recent announcement that the games will in fact be postponed, that should be off the table.

When asked about the possibility that large numbers of coronavirus-related deaths are being ignored or written off as pneumonia, Matsumoto Tetsuya, a professor of public health at the International University of Health and Welfare Graduate School in Otawara, said that it was possible but not likely. “While we can’t rule out the possibility, deaths by pneumonia of unclear origins are rigorously investigated,” Matsumoto said.

Concern moving into spring

It nevertheless remains clear that under-testing is masking the extent of the infection in Japan.

A leap of cases in Tokyo may prove that the virus has been spreading throughout Japan via mild and asymptomatic spreaders, and just as people begin to let their guard down, a newfound explosion of cases will emerge.

“This is why I feel it is so important to test random, representative samples of the population, to see where we stand,” said Ioannidis. “Otherwise, it may be like trying to pick molecules of air with our fingers, given that so many cases are asymptomatic or very mildly symptomatic and go undetected. If the virus is shown to be already widely spread, [the] focus should be on preparing the health system as well as one can, plus fiercely protecting high-risk individuals.”

“From last week, we’ve also started to see a lot of cases in people returning from overseas,” Sato said. “I’m concerned that when the number of cases reaches 3,000 to 5,000, the health care infrastructure will start to become overwhelmed.”

People take photographs of the Chidorigafuchi Moat, which banned paddle boats during cherry blossom season to discourage visitors amid the coronavirus pandemic, in Tokyo on March 26, 2020.

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People visit the cherry blossoms in bloom at Ueno Park in Tokyo, Japan, March 26, 2020.

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There is also concern about the government’s border-control approach. Kim points out that a pillar of the Japanese response has been to limit the entry of foreigners from affected regions into the country.

“However, there are many loopholes,” Kim said. “Foreigners are not a sole risk factor of incoming diseases. South Korea cases reveal that the majority of cases are introduced by Korean citizens returning from travel and business trips abroad.”

Japan recently extended self-quarantine regulations to apply to visitors from Europe and the US, but these quarantines are self-enforced, unlike in China and Taiwan.

Based on the latest round of recommendations from the expert panel, the Japanese government is seeking “thorough behavioral changes” to improve citizens’ response to the coronavirus and ensure that people avoid places that meet the three conditions of poor ventilation, dense crowds, and dense conversation.

Faced with skyrocketing infections, much of Europe and the US have moved toward lockdowns. Japan hasn’t. The government insists that it doesn’t need to, citing that in some areas, almost all of the local coronavirus patients have been identified via contact tracing.

But Sato warns that as long as cases continue to rise, no one can afford to take their foot off the gas: “Even if we continue with the measures already in place, the spread will not end.”

It’s a worrying sign for a country that’s clearly ready to take off the masks and enjoy the cherry blossoms.