The Asian Corporate Governance Association has published a summary of the laws and rules in Asian countries regarding requirements for independent directors and their role.This highly useful summary isavailable for registered BDTI users to see and download in the Data Libraryat:
http://bdti.mastertree.jp/f/bnlmaoxj
The Board Director Training Institute (BDTI) is a "public interest" nonprofit in Japan dedicated to training about directorship, corporate governance, and related management techniques. It is certified by the Japanese government to conduct these activities as a regulated nonprofit. Read a summary about BDTI here, and see a menu of its services for both corporations and investors here.