Japanese Foreign Minister Toshimitsu Motegi told reporters that the travel restrictions between Singapore and Japan might be eased from September after reaching the agreement with the Singaporean counterpart Vivian Balakrishnan at their meeting in the Southeast Asian country. 

The travelers are required to do 2 weeks of self-quarantine after entering the country now. After this agreement,  the eligible business travelers will be exempt from doing quarantine, however, they are asked to submit an itinerary of their stay, PCR check certificate, etc. Travelers are also asked to not use public transportation and avoid contact with random people or crowds. 

Japan, which currently bans the entry of all foreign nationals from 146 designated countries and regions in principle. After the Coronavirus pandemic outbreak, the Japanese government has started to negotiate with 16 more countries to ease travel restrictions.

Source: シンガポールとビジネス往来、9月から　外相会談で合意