Prime Minister KIshida announced on Dec 27, 2022 that Japan will tighten its border controls for travellers from China from Dec 30, 2022, as the latter nation is seeing a surge in COVID-19 infections
Regardless of nationalities, any person who had stayed in China within 7 days prior to arrival to Japan will be tested for COVID-19 upon arrival.
It is applied to any person who arrives to Japan from China via other countries, too.
Those who test positive will be required to quarantine at designated facilities for seven days.
The quarantine period for those who test positive is expected to be seven days if they have developed symptoms. For those who are asymptomatic, the period will be shortened to five days if they test negative on the fifth day, according to the health ministry.
Due to above, arranging a joining crew member from China to Japan will be risky as the ship may have to sail away from Japan before the quarantine period ends in case test positive.