This study explores how participatory design and interactive storytelling could empower rural-to-urban migrant children in China's educational system. Through a two-year ethnographic fieldwork at a migrant school in Beijing and co-design workshops with 11 students, we developed SuperPhone, an interactive storytelling device that allows children to share and listen to personal narratives. Drawing on Zimmerman's model of psychological empowerment, our design process engaged children as active participants rather than passive users. Field deployment revealed how children used this technology to process academic anxieties, navigate identity confusion, and cope with disrupted social relationships. The stories collected through SuperPhone (286 interactions, 54 original narratives) demonstrate that children created meaningful spaces for connection and expression through storytelling. This study shows how participatory design can create opportunities for self-expression while empowering children to shape technological solutions that address their unique social and emotional needs.