Corporate sustainability efforts in Southeast Asia, one of the most polluted regions globally, have become increasingly more prominent in the hospitality sector. Bourgeoning research indicates that such efforts drive the triple bottom line while simultaneously enhancing the customer experience. Organizational Citizenship Behavior (OCB) and the theory of green purchase behavior (TGPB) suggest that green products and services influence hospitality workers and customer behaviors and decision-making, loyalty, and psychological needs, shaping sustainable purchasing behavior. Sourcing sustainable suppliers has provided hospitality organizations with a way of introducing circular business practices that satisfy both internal and external stakeholders. This case study focuses on Glassia, a Vietnamese company that provides reusable glass bottled water to hospitality partners as an alternative to single-use plastic containers. By recollecting, sterilizing, and refiling glass water bottles, the company seeks to be competitively priced, change consumer behavior and reduce plastic pollution, as well as transform a linear value chain into a closed-loop decentralized system. This chapter analyses the Glassia case study through the lens of OCB and TGPB, simultaneously assessing the effectiveness of Glassia's approach in influencing the green purchasing behavior of both internal (hospitality providers) and external (hospitality guests) stakeholders. Implications for practitioners and policymakers and directions for future research are discussed.