JIS X 8341-3 is Japan’s Japanese Industrial Standard covering web content accessibility, currently in its 2016 revision and derived from WCAG 2.0. It was developed by Japan’s Web Accessibility Infrastructure Committee and is recommended for public-sector websites through the government’s own operational accessibility guidelines.
Compliance with JIS X 8341-3 is technically voluntary rather than backed by the kind of civil litigation common in the US, but it functions as the de facto national benchmark that Japanese government agencies, and many large private organizations, audit their websites against.