With brand trust acting as a mediating variable, this study looks at how young adults in Surabaya decide which Casio watches to buy based on product quality and brand image. A structured questionnaire was disseminated through a variety of social media channels to young adults who were familiar with the Casio brand in order to gather primary data. In today's world, where smartwatches are progressively dominating the watch industry, conventional timepieces remain important to many individuals because they provide timeless design, workmanship, and a feeling of legacy that digital competitors frequently lack. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to evaluate the hypothesized correlations among the 100 valid replies from the 122 respondents. The results show that brand trust, which in turn mediates their impact on purchasing decisions, is strongly influenced by product quality and brand image. The most important component was found to be product quality, however brand image indirectly helped by increasing brand trust. These findings demonstrate how crucial it is to uphold high standards for products and develop a powerful brand identity in order to build trust and influence consumer behavior in a cutthroat market. For marketers looking to maximize branding tactics for young adult consumers, the report provides insightful information.