The present study explores the East Asian international sojourners' identity performance and negotiation in the host country as a part of cultural adjustment. In the process of cultural adaptation, individuals negotiate their identities while they interact with others in the host country. Even though a number of researchers have studied international sojourners' communication behaviors and cultural adjustment in the host country, they did not paid attention to the diverse cultural groups that they interacted with in the host country. To explore the communication behaviors of East Asian international sojourners, I interviewed individuals (N=26) from four East Asian countries (South Korea, China, Japan, and Taiwan). The collected data were analyzed with an emergent thematic analysis.The result indicated that East Asian international sojourners negotiated and performed their identities when they communicate with others in the process of cultural adjustment. First of all, when East Asian international sojourners interacted with people from their home-cultural group, they (a) avoided home-culture group, (b) showed their American side, (c) approached cultural informers, (d) experienced instant connection, (e) de-emphasized Americanness, (f) were extra polite, (g) shared home culture. Secondly, they showed nine communication behaviors when they interacted with host-culture groups: (a) following American norms, (b) experiencing distance, (c) communicating with ease, (e) avoiding certain communication topics, (f) becoming more expressive, (g) keeping their home-culture way of communication, (h) effort driven negotiation, (i) strategically interacting for benefit, (j) working to make a good impression. Finally, they actively interacted with diverse groups and set up new version of identity regardless of cultural groups they communicated with. The analysis of interviews also revealed that East Asian international sojourners experienced two types of tension, as well as the environment of less tension during communication in the host country. They felt pressured to selectively assimilate to the host country. To negotiate the tension, they followed American norms to be successful. Next, they experienced tension between the two cultures (home culture and host culture). They chose code-switching communication styles based on the audiences in order to resolve the tension. Finally, in the host country, they felt less pressure as they were physically away from their home culture. In the environment of less pressure, they chose communication behaviors based on their preference. This research makes a contribution by (a) offering lived experiences of East Asian international sojourner's identity management in the host country, (b) suggesting new perspectives to the integrative theory of cross-cultural adjustment, anxiety and uncertainty management theory, and co-cultural theory to better understand the communication behaviors of East Asian international sojourners, and (c) providing practical implications to individuals and organizations that have chances to interact with East Asian international sojourners.