The Korean Residents Union in Japan(also referred to as Mindan) was compared with the Federation of Korean Associations in Japan in terms of nine items about organizational structure and the organizational satisfaction of the members. First, Mindan had a nationwide network, whereas the Federation of Korean Associations in Japan was primarily based in Tokyo. There were common denominators between the two organizations in that both were Korean-friendly, did external activities for the sake of Korean residents in Japan, sought after coexistence and coliving between Korean residents and Japanese people, and mainly consisted of those who had the Korean nationality. They were different from each other only in two regards. The former was composed of oldcomers, and the latter consisted of newcomers. And the former coped with sensitive issues between Korea and Japan in an active way, and the latter did it in a passive way. Second, when the satisfaction level of the members of the two organizations was analyzed, there were statistically significant differences in four items: whether to look at the participation of Korean residents who were naturalized in Japan in a negative manner or not, awareness on the necessity of financial aid from the Korean government, which would be necessary for organizational development, awareness on the transparency of budget execution, and whether their opinions were well reflected in organizational policy setting or not. Third, the key factors to the revitalization of the organizations were to recover broken communication channels, to publicize the identity of the organizations, to keep attracting new members and to ensure the independence of finance. Fourth, the two organizations should be integrated in consideration of the usefulness of their unity to boost the influence of Korean residents on Japanese society and to create a Koreafriendly unified association of Korean residents. That will serve to remove unnecessary competition, to solve the aging problem of Mindan, to attract the younger generations and to be of use for the acquisition of local election franchise, which will, in turn, make a great contribution to their own reinforcement and revitalization.