The German-Japanese Colloquium on Administrative Law institutionalizes and strengthens the long-standing connection between German and Japanese administrative law scholarship. This volume brings together the contributions of the 2nd German-Japanese Colloquium on Administrative Law, which took place at the University of Tokyo in April 2025, two years after the inaugural event in Heidelberg in 2023. This volume focuses on administrative procedures in transition, taking into account governmental, administrative, and judicial aspects. New requirements for efficiency, transparency, and participation are changing the structure of procedures and challenging the legal systems of both countries. The following topics are covered in detail: administrative court legal protection between subjective legal defense and objective legal control, functions of administrative procedures in transition, errors and consequences of errors in administrative procedures, and administrative functions of the government. Further attention was paid to the current reform discussions on the acceleration of administrative procedures in Germany and on informal administrative action in Japan.