The ongoing debate on “fast fashion” and environmental impact has created a great divide amongst fashion industry players as well as consumers. The two sides of the narrative posits the upsides to retail manufacturing and consumer accessibility, whereas the other offers responsible consumption with long-term impact. Where fast fashion is defined as clothing manufactured at a rapid production cycle—from design to retail—-for the purpose of creating or leveraging trends. This innovation in the supply chain has enabled clothing companies to introduce capsule collections over a two-week period. The United Nations Environment Programme (2019) published an article citing the fashion industry as responsible for two to eight percent of global carbon emissions, and with implications expanding to a social context. With cognizance of the United Nation’s Sustainable Development Goal (UN SDG) 12, the conversation leads to a study on sustainable consumption and production patterns. One such company now participating in this conversation is UNIQLO. Considered among global players in the fast fashion sector, the company has decided to consciously depart from this approach towards a more sustainable model. This study focused on an investigation of the customer engagement and the corporate sustainability reputation of UNIQLO consumers as mediated by customer satisfaction. The main concepts include two independent variables of customer engagement, the dependent variable of purchase intention, and the mediator of customer satisfaction. The researchers intend to take a quantitative approach via survey questionnaire, adapting items from measurements scales in previous studies. A total of 449 responses will be obtained from students from Metro Manila, Philippines. The data obtained will undergo statistical tests, including Cronbach’s alpha, Pearson’s correlation, simple linear regression, multiple linear regression, and mediation analysis. The results highlighted, firstly, that the variables of customer engagement, corporate sustainability reputation, and customer satisfaction significantly correlate and impact purchase intention. Secondly, it indicated that customer engagement and corporate sustainability reputation can substantially influence purchase intention. And, thirdly, the observation on customer satisfaction partially mediating the relationship between customer engagement and corporate sustainability reputation on purchase intention. As we accelerate towards the United Nation’s call to action on the SDGs come 2030, this study may bear significance to fashion industry practitioners, consumers, the Academe, on legislation, and the UN Alliance for Sustainable Fashion towards shifting the narrative on the fashion sector.