According to Hofstede’s (2003) often quoted survey, Japanese and Thai cultures rank high on the collectivist scale and both cultures attach the greatest importance to group harmony. Accordingly, we should see similar characteristics in Japanese and Thai speakers during discussions within their respective social groups. However, this is not the case. This paper examines social talk during the task-oriented interaction of Japanese and Thai speakers. The analysis focuses on how the speakers of Japanese and Thai present themselves and construct rapport in casual group talk. Using the concept of consciousness deployed in ‘idea units’ (Chafe 1980, 1994) and some semantic considerations, I identify three major differences in rapport construction between Japanese and Thai speakers. First, Japanese participants prefer to build common ground through discussion of communal topics and through dealing with the comprehensiveness and the orderliness of the situation, whereas Thai participants incline toward Individual-oriented topics and independent styles of talk. Second, the Japanese show a preference for using softening devices and conventionalized expressions in group discussion while the Thais tend to use intensifiers and spontaneous expressions to indicate involvement and create a friendly and fun atmosphere. Third, the Japanese like to demonstrate the minimization of self and the relevancy between the self and the collective whereas the Thais value the capitalization of the self and the strengthening of personal relationships. Japanese and Thai communicative styles can be viewed as reflection of the different way the two cultures conceptualize the notion of rapport and the self. With regard to the component of rapport management (Spencer-Oatey 2000), the Japanese place more emphasis on the observation of sociality rights, while the Thais incline toward the management of face. This suggests that rapport construction in collectivist cultures may possess totally different characters.