This study examines approaches to the internationalization of Japanese universities by focusing on the effects of institutional structures and cultures. Using a qualitative case study method, the research examines the following question: "How do institutional structures and cultures affect the internationalization of education in Japanese universities?" While its philosophical importance has acquired wider recognition, institutional trials for internationalization vary extremely. By considering different factors, the study's findings shed light on the internationalization strategies, approaches, and management techniques suited to different university types in Japan. Three arguments are advanced. First, four possible patterns of approaches to institutional internationalization are explored based on structural approaches and patterns of cultural behaviors. Second, senior leadership, the roles of international offices, and internal communication are examined as important factors in the practice of institutional internationalization. Third, a more intensive effort to interrelate structural and cultural aspects is required for the further advancement of institutional internationalization.