This article seeks to understand why the uptake of 'third generation' enduring powers in Japan has been disappointing from the perspective of reformers who introduced the powers in 2000. In addition to questions about optimum design of this particular legal instrument, it is an opportunity to explore deeper questions about regulation and the role of law and the market in ageing, post-industrial societies such as Japan. First, the article explains the form that enduring powers take in Japan. Second, it presents statistics on the uptake of enduring powers. Third, the article presents possible reasons for this low uptake, including unsuitable social norms, a lack of awareness, excessive regulation, unresponsive doctrine, and entrenched judicial values. Finally, the article concludes that while these reasons all have explanatory value and are not easily disaggregated, comparative analysis presents some promising developments in Japan such as the growth in candidates to take on enduring powers who are regulated and organised through legal professions, civil society, local government, and the court system. At a deeper level, the article concludes that the fate of enduring powers turns not only on regulatory and doctrinal levers but also on the relative strengths within Japan?s continuing legal development of divergent views on the imposition of formal legal norms and market mechanisms upon relationships previously regulated by informal social norms or administrative decree.