All classrooms must be thoroughly ventilated and students should avoid gathering in clusters, Japan's Education Ministry said yesterday as it issued guidelines ahead of schools reopening next month after a long break amid the coronavirus outbreak.
Among other things, students and teachers are advised to wear masks when speaking to one another in close contact, and take their temperatures daily.
Home-learning measures should also be in place to ensure that students do not fall behind if they are unable to attend classes.
A vast majority of schools nationwide had heeded Prime Minister Shinzo Abe's appeal on Feb 27 for a month-long closure to keep the virus spread in check.
While there has been "no marked improvement" in the Covid-19 situation, Education Minister Koichi Hagiuda said it was untenable to keep schools closed for longer.
"We want schools to prepare to reopen after the spring break without lowering their guard, on the premise that it continues to be a severe situation where individuals should continue to practise self-restraint," he told reporters.
Most schools in Japan are set to open on April 6; this may vary according to local governments.
Despite the official calls for restraint, many members of the public have already begun to loosen their guard, with rush-hour trains remaining crowded and people going ahead with cherry blossom viewing parties and attending sports events.
The call for schools to close had been an abrupt, top-down decision made by Mr Abe without medical experts' advice, incurring a backlash from working parents who did not have sufficient time to react, and the U-turn comes despite a steady increase in infections.
As of 10.30pm yesterday, there were 1,209 cases in Japan, with a jump of 64 in just five hours.
Tokyo has 171 cases, with the highest single-day rise of 17 cases. It yesterday overtook Hokkaido, which had the most cases in Japan.
Japan has been testing for Covid-19 at a fraction of its full capacity. The Health Ministry has rejected calls for more widespread tests, saying that this may lead to unnecessary panic and inundate the healthcare system, although critics have said this could result in milder cases slipping under the radar.
Already, Japan is seeing rising numbers of "unlinked" cases. These include 154 infections in Tokyo, whose Governor Yuriko Koike said she will not rule out a total lockdown if the number of cases spikes.
The government yesterday called on schools to maintain proper cleanliness, and ensure social distancing takes place at all times.
Mr Hagiuda said that while the national government will continue to collect data and give advice, it will leave it up to local municipalities to decide on the best course forward, since the prevalence of infections drastically varies between areas.