The data related to the COVID-19 outbreak in Japan is not standardardized.
Links in the left column are to pages on prefectural websites, and on those pages (all in Japanese0, you'll find detailed information about COVID-19 casest, or not. It depends on the prefecture.
Pages linked in the right column generally include prefectural hotlines and FAQs. Some prefectures offer info and consultations in languages other than Japanese.