Designing effective educational toys requires a profound understanding of children's needs, perspectives, and interests. However, gathering reliable and valid data from preschool children remains a significant challenge due to their cognitive and linguistic limitations. Existing user research methods are often one-dimensional, fail to adequately engage young participants, or lack a systematic framework for execution and data analysis. This study addresses this gap by developing and validating a comprehensive, interactive user-research framework specifically tailored for preschool children in the context of toy design. The ultimate goal of this research is to provide an efficient tool for designers and researchers to gain a deeper understanding of the children's world through an engaging and meaningful process, thereby enabling the creation of products that genuinely resonate with their needs. This study employs a fundamental-developmental research design with a qualitative approach. An innovative user-research model, titled "Operation Blue Rescue," was designed and implemented. The model strategically integrates storytelling, drama, role-playing, and creative arts (drawing and collage) into a four-stage process: 1) Rapport-Building, 2) Narrative Framing & Problem Introduction, 3) Collaborative Ideation, and 4) Data Validation. To assess the framework's effectiveness, a case study was conducted with four six-year-old preschool children (2 boys, 2 girls). The central theme for the study was designing a toy to teach water conservation. Data were collected through unstructured interviews and non-participant observation, meticulously documented via video and audio recordings. The collected qualitative data were systematically analyzed using the Grounded Theory approach, involving open, axial, and selective coding to identify emergent themes and patterns. The results confirm the high efficacy of the "Operation Blue Rescue" model. The narrative structure, featuring relatable characters like a facilitator (referred to as "Mr. Blue") and a communicative puppet, successfully mitigated children's initial shyness and fostered a safe, engaging environment for active participation. This interactive approach allowed the children to feel like they were part of an exciting adventure rather than a formal question-and-answer session. The use of multi-modal expressive tools, such as drawing and collage, enabled children to articulate complex ideas and emotions that were difficult to express verbally. The findings underscore the model's success in transforming the research process into a meaningful, goal-oriented play experience. Furthermore, the application of Grounded Theory proved to be a robust and effective method for structuring the complex qualitative data. This process successfully translated rich, raw data into actionable insights for the toy design process, demonstrating that with an appropriate analytical framework, qualitative information can yield reliable and valuable results. This research contributes a validated, replicable, and methodologically sound framework—"Operation Blue Rescue"—for conducting user research with preschool children. It provides designers and researchers with a strategic roadmap that bridges the gap between child-centric engagement and rigorous qualitative data analysis. By integrating proven learning theories such as Constructivism and Observational Learning into a practical, multi-stage model, this study offers a valuable tool for uncovering the deep-seated needs and perspectives of young users. Ultimately, this framework will significantly facilitate the creation of more meaningful and effective educational products, paving the way for future research in the field of child-centric design.