Here are some resources that I've found helpful for finding public domain information on SARS-CoV-2 transmission in Japan. Makoto - Infodemic (@makoto_au_japon ) provides English-language summaries of Japanese cases, with links to reports from the Japanese Ministry of Health, local government, or other detailed reports.  Google Translate works well on most of these pages. Japanese Ministry of Health press releases on SARS-CoV-2 cases and outbreaks Chiba Prefecture information dashboard for confirmed cases and outbreaks - some good reports by setting.

COVID-AMP Analysis and Mapping of Policies Covid AMP - Analysis and Mapping of Policies  is a database of policies and plans  to address the pandemic, with visualisation tools, from  Georgetown University Center for Global Health Science and Security and Talus Analytics . US-centric but increasingly expanding to include other countries.  Twitter thread explaining all of the different functionalities (with visuals). Government Response Stringency Index - Our World In Data The Government Response Stringency Index from our World In Data is a composite measure based on nine response indicators including school closures, workplace closures, and travel bans, rescaled to a value from 0 to 100 (100 = strictest response).