The paper ('Institutional Economics and Japanese Studies') contains three contributions to a workshop as part of a workshop series on 'Organisation and Order of the Japanese Economy'. Stefan Voigt introduces the reader to the assumptions, analytical methods and areas of application of institutional economics as a theory-based approach. Dirk Wentzel makes use of the established typology of institutions and discusses a peculiar type, namely self-regulation. Andreas Nabor studies the reform potentials, path dependencies and adaptive efficiency of the Japanese financial system, applying institutional economic methods.