This study employed the framework of grounded theory methodology to analyze the following questions: ‘What are the experiences of Korean TCK adolescents in terms of their transnational relocation during overseas sojourn?’ and ‘What is the process through which they undergo in the formation of their identities?’. For data collection, the researcher conducted interviews with a total of 18 Korean secondary students who hold Korean nationality while sojourning abroad. The causal conditions were identified as attempts to acquire cultural capital and transnational relocation. The factors influencing the confusion experienced by participants were identified as highly mobile lifestyle, the need for multiple languages, differences in educational approaches, and cultural disparities. Korean TCK adolescents were observed to employ various adaptation strategies using resources within their micro-, meso-, and macro-systems. Ultimately, the process of identity formation for Korean TCK adolescents was identified as a progression toward ‘Becoming Global Citizens.’ This process was analyzed to unfold in five stages: the transition stage, the confusion stage, the adjustment stage, the identity reaffirmation stage, and the pursuit of global citizenship stage. Finally, this study concluded with a discussion on its limitations and recommendations for future research.