Japan reopens borders for all foreign visitors especially 10 countries and regions that have a low number of covid-19 infections from October 1st.
The foreign travelers including students and business people are allowed to enter the country with permits to stay for some time.
These travelers must be accepted by entities or organizations capable of ensuring they have tested negative for the virus before entering Japan. After arrival, they have to stay in self-isolation for 14 days and avoid using public transportation during the period.