The number of confirmed cases has climbed to 5,292 after new 320 cases were found, according to public broadcaster NHK.
Most of the new coronavirus cases were found in the capital Tokyo, where total number has crossed 1,500.
On late Tuesday, Prime Minister Shinzo Abe declared a state of emergency in seven prefectures, including Tokyo.
The infected people included 96 Health Ministry and quarantine officials. The death toll in the country has reached 117 — including 11 from Diamond Princess cruise ship.
712 coronavirus cases at the ship take the tally in the country to 6,004.
South Korea launches online classes
In South Korea, students started receiving lessons online at their homes from Wednesday, according to local Yonhap news agency.
The number of new cases is decreasing in South Korea for the past seven days.
Health officials said that just 39 new cases were detected on Wednesday, bringing total number of cases to 10,423.
At least 204 people have died of the coronavirus since the beginning of the outbreak in the country and 6,973 people have recovered.
Since appearing in China last December, the virus has spread to at least 184 countries and regions, according to figures compiled by the U.S.-based Johns Hopkins University’s Coronavirus Resource Center.
Nearly 1.5 million cases have been reported worldwide, with nearly 90,000 deaths, and almost 333,000 recoveries.