Starting from the 11th of October, Japan is allowing exemptions for short-term visitors to enter the country without a visa.
Currently, 68 countries/regions. please refer to The ministry of Foreign Affairs of Japan
Visitors who enter Japan for short-term stays for tourism are no longer required to purchase package tours.You will need a valid vaccination certificate or a Covid-19 negative test certificate (the test must be conducted within 72 hours before your scheduled departure time) to come to Japan.

For more info
The Ministry of Health, Labour and Welfare
The ministry of Foreign Affairs of Japan