This case study explores style-shifting in female professor–student conversations for identity and stance from the viewpoint of constructivist discourse theory. The results show that the interactants do not mutually swap the desu/masu (formal) form. While they preserve the hierarchical relationship with fit style choice, they attain plural stances like affective and personal stance, self-presentational stance, professional stance as well as story-telling persona. While three students mainly employ the desu/masu form, thereare variances in professors’ style-shifting options. The professors regularly reverse the style to the plain form when complimenting, and shift to the desu/masu form when requesting, seeking information, or changing the conversational topic. These results emphasize the assertion that style-shifting is really one of the signficant linguistic resources to build participants’ multiple social personae or, utilizing Bakhtin's (1981) term, “heteroglossia” in daily conversation. The study also proposes that students and professors display divergent style-shifting patterns according to setting types.