The rash of new cases has the Japanese government scrambling to make sure the virus doesn't spread any further.
Prime Minister Shinzo Abe said, " We're setting up an expert panel consisting of front-line specialists on infectious diseases to strengthen measures."
The prime minister suggested that officials will work with local governments to boost testing and treatment systems.
The foreign ministry has raised its travel alert for the city of Wenzhou in the eastern Chinese province of Zhejiang.
Foreign Minister Toshimitsu Motegi said, "We've decided to raise the infectious disease warning for the city of Wenzhou to level three, which urges Japanese nationals to avoid all travel there."
Hubei Province is also at alert level 3. The rest of China is at level 2, meaning Japanese nationals are advised against any non-essential travel.
The government plans to send a fifth chartered flight to evacuate Japanese nationals from Hubei on Sunday.
So far 763 people, including Chinese spouses of Japanese citizens, have been evacuated on four chartered flights since late last month.
145 of them, on the third flight, were tested for the virus after spending a 12-and-a-half day observation period at government facilities. One tested positive. The remaining 144 will be free to go home.