Sources say a pilot who stayed in Britain and a member of his family have tested positive for a new variant of the coronavirus and are being hospitalized in Tokyo.
The National Institute of Infectious Diseases analyzed samples collected from them.
Japanese authorities had reported 3,877 new cases of the coronavirus as of 8 p.m. on Saturday.
They reported 47 deaths, including 11 in Osaka, 10 in Tokyo, 8 in Hyogo and 6 in Aichi.
The spread of the new coronavirus is threatening the supply of blood for transfusions in the Tokyo Metropolitan area.
The Japanese Red Cross Society's regional blood center says donations have fallen below monthly targets since April, when a state of emergency was declared that caused people to work or study at home.
The Japanese government has decided to suspend new entries of foreign nationals in an effort to stop the influx of a new coronavirus variant.
The new strain has been spreading outside Japan in at least 14 countries and one territory. It is believed to be more contagious than the original virus.
The Japanese government has tightened its rules for travelers from South Africa, where a new variant of the coronavirus was detected.
Japan started refusing arrivals from South Africa on Saturday. Japanese and non-Japanese who have resident status in Japan are allowed entry. But they are being asked to self-quarantine for 14 days on arrival in the country.
The Japanese government plans to seek an early conclusion to talks with the administration of president-elect Joe Biden on its share of the cost of stationing US forces in the country. Biden is set to take office next month.
The two countries have not reached an agreement in working-level talks which started last month. It is unusual for the discussions to stretch to the following year.
The Japanese government faces both technical and policy challenges in reaching the goals it has set to achieve net-zero emission of greenhouse gases by 2050.
The government compiled specific targets for 14 sectors on Friday.
A Japanese organization combating online pirated manga has estimated that losses from the illegal versions reached the worst monthly level in November.
The Authorized Books of Japan, or ABJ, says websites showing pirated titles have been cropping up.
Japan's health minister says five people returning from Britain have tested positive for a new variant of the coronavirus.
Tamura Norihisa told reporters on Friday night that the five were earlier found to be infected with the coronavirus after tests at two airports in Japan.
Japan's health ministry says it will tighten entry restrictions on travelers from South Africa in response to the spread there of a relatively highly contagious variant of the new coronavirus. The ministry officials say that the stepped-up measures will take effect on Saturday.
They say Japan will refuse new entrants from South Africa for the time being. They added Japanese and non-Japanese who have residential status in Japan will be asked to self-quarantine for 14 days when they enter the country.
Giant advertising screens on buildings overlooking a popular scramble crossing near Tokyo's Shibuya Station will be turned off earlier than usual on New Year's Eve, as one of the efforts to deter people from gathering amid the coronavirus outbreak.
The Shibuya Ward Office asked operators of 13 large screens in and around Shibuya's main intersection to switch the screens off from 11 p.m. on December 31, two hours earlier than last year.
Japan's health ministry says five people who returned to Japan from Britain have tested positive for a new variant of the coronavirus.
The five were earlier found to be infected with the coronavirus at an airport in Japan.
Japan's prime minister said his administration will consider revising the law so that subsidies and penalties can be used in combination to enforce shorter business hours at bars and restaurants.
Suga Yoshihide mentioned the plan at a news conference on Friday. He called on people to avoid gatherings during year-end and New Year holidays to contain a surge in coronavirus cases.
Former Japanese prime minister Abe Shinzo has apologized in parliament over false remarks he made repeatedly to lawmakers about his political funds. The apology came a day after one of his secretaries was convicted of misreporting about 300,000 dollars in connection with parties for Abe's supporters.
"Today, I would like to explain the facts again at this committee and correct my answers. I would like to offer my deepest apologies to all Diet members," Abe said.