Japan has no comparable law to ERISA, the comprehensive law regulating corporate pension funds, requiring funding and many other features, and enforced by the Department of Labor. Here's an excellent summary of ERISA in a report made to the U.S.Congress:
Summary of the Employee Retirement Income Security Act (ERISA)
http://bdti.mastertree.jp/f/lrk5ef1v
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.