In this session, we will present practical case studies of implementing generative AI in Yahoo! JAPAN Flea Market. We will share insights gained through our step-by-step approach, starting from “product description generation,” progressing to “product title generation,” and ultimately developing the capability to “generate product information from a single image.” We will discuss our user value-centered approach rather than technology-driven implementation, establishing evaluation methods, and decision-making within practical constraints—all practical learnings from the field. For those working on generative AI projects, we will provide concrete tips on how to implement while maintaining a balance between technology and value.