This paper examines the relationship between democracy and Citizen’s self-development. In particular, it focuses on Iris Young’s communicative democracy. According to Young, communicative democracy is a democracy in which the perspectives of the socially marginalized citizens are not excluded in the process of public decision-making and communication. It purposes to show how democratic communication affects the self-development of socially marginalized citizens in light of communicative democracy, and as an example, how democratic communication leads the self-development of participants in the Sewol ferry movement. For this purpose, the paper aims to ultimately contribute to the establishment of a more just and substantive democracy theory by enabling an expanded understanding of democratic subjects and their communication methods. In the end, while existing democracy focuses on periodic elections and limited to understanding the way political communication and decision-making. Ultimately, while existing democracy only understands the political communication and decision-making method centered on periodic elections, this paper intends to contribute to expanding the meaning of democratic communication and citizen’s self-development through communicative democracy.