AWS Well-Architected Tool is now available in the Asia Pacific (Tokyo) Region and the tool has been localized into Japanese. AWS Well-Architected Tool helps you review your workloads against AWS architectural best practices, and provides guidance on improving your cloud architectures.

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/09/aws-well-architected-tool-now-available-tokyo-region-and-localized-into-japanese/