Despite the growing attention on the conflicting dimensions of corporate sustainability, little is known about the tensions experienced by managers when adopting global corporate sustainability standards. In East Asia, more specifically, these standards are often viewed as strategic tools that differ from the indigenous and normative understanding of environmental and social contribution. In this paper we take a cultural viewpoint to examine and explain the tensions—and reactions to these tensions—of corporate sustainability managers in South Korean and Japanese multi-national corporations tasked with the implementation of global standards. Through 65 in-depth and comparative interviews conducted in Seoul and Tokyo between 2012 and 2017, we found that corporate sustainability managers in South Korea and Japan similarly encounter societal-commercial, traditional-new and individual-collective tensions. Nonetheless, our evidence indicates that they react to those tensions in contrary ways because of the roots of their indigenous sustainability, which are predicated upon different interpretations of Confucian ethics. This paper contributes to the literature on corporate sustainability by bringing into the analysis the tensions of corporate sustainability managers in East Asia.