In chIn chapter 6, Dimitri Vanoverbeke looks closer at East Asia’s first experience with constitutionalism by explicating the process of constitutionalism in Japan. In this chapter, he argues that the constitutionalism has two dynamics; top-down and bottom-up or state-centred and society-centred. Constitutionalism includes a complex, long-duree process of the transformation of goals and ideas, and this process determines how future developments and reforms regarding constitutionalism are approached in a given society. Japan’s experience is important in understanding how historical paths have a lasting impact on constitutionalism and on the understanding of the Global Constitutionalism debate. Vanoverbeke also goes beyond the case of Japan to analyse the recent dynamics of institution building in Southeast Asia, where principles and constitutional norms are debated and conferred a place in new formal systems related to ASEAN. The dynamics that he uncovers in the recent ASEAN institutional reforms conform with the long-term developments regarding constitutionalism in Japan and should be considered in revisiting strong criticism from East Asian scholars of Global Constitutionalism.apter 6