KATO Jotaro is a PhD candidate at Graduate School of Asia Pacific Studies, Waseda University. He has started his PhD from April 2017 after supporting undocumented migrants in Japan as a case worker of NGO. His majors in international labor mobility and global sociology. His research interest is on undocumented migrants, refugees and migration policy in Japan. He uses qualitative methods, with the belief that grassroots level observations, participation, interaction, and interviews contain as well as reveal the workings of greater thematic issues. He was a visiting scholar at Queens College, City University of New York (from August 2018 to February 2019) funded by JSPS Overseas Challenge Program for Young Researchers. He is currently a research fellow (DC2) at Japan Society for the Promotion Science. He is also a visiting lecturer at Hosei University, University of the Sacred Heart and Tokyo Women’s Christian University. His latest publication is “Living with ‘illegality’ : What makes it possible for irregular migrants to live in Japan?” Migration Policy ReviewVol.11 (May, 2019).