This chapter focuses on the participants’ social networks. The analysis evidences the key roles of transnational social network development, network embeddedness, and network maintenance. These roles are central to individual academic habitus and mobility agency development along personal transnational migratory trajectories. They are also critical to upward academic mobility in Japan. The participants’ narratives and illustrations identify five types of social networks related to the academic mobility of migrated academics: primary family, educational and professional, international marriage, ethnic community and religion, and local Japanese social networks.