Mental wellbeing has become a crucial aspect of overall health and has drawn increased attention to mental health concerns. Research in human-computer interaction (HCI) has explored how technologies can support mental wellbeing and address mental health issues. However, current research predominantly reflects Western cultural perspectives, leaving gaps in our understanding of mental wellbeing, coping strategies, and digital tools for mental wellbeing support from Eastern cultural viewpoints. To start to address this disparity, we interviewed 19 Taiwanese emerging adults aged between 18 and 29—a demographic uniquely susceptible to mental health challenges due to the transitional nature of this life phase. We explored their conceptualization of mental wellbeing, the challenges they encounter, the strategies they employ for managing mental wellbeing, and the role of digital tools in this process. The results highlight the intricate influence of cultural, political, social, and individual factors, and their interactions on mental wellbeing.