Although contextual influences on L2 motivation have been widely acknowledged, studies of underrepresented learners of less-commonly-taught languages have been extremely rare. To fill this gap, this study aimed to promote the local understanding of motivation among Vietnamese learners of Korean within the theoretical framework of L2 selves and regulatory focus. In particular, this study qualitatively explored L2 selves through an open-ended questionnaire and developed a measure of L2 regulatory focus, outlining the distinct motivational strategies associated with the ideal and ought-to L2 selves. The participants completed a survey consisting of the open-ended ideal and ought-to L2 selves and closed-ended regulatory focus scales. The promotion- and prevention-instrumentality scales were tested for their applicability to the learner population. Additionally, the promotion- and prevention-motivated behaviour scales were created and validated through statistical analysis with the thematically coded L2 selves. The results showed the strong emphasis on intrapersonal and career domains of the L2 selves. Theoretical, practical, and policy implications are discussed.