This paper describes a research study regarding intergenerational story sharing of the elderly living in the nursing home, including four iterations, applying a Research-through-Design approach. It started from an exploration prototype named Interactive Gallery(1stiteration), and its findings helped to narrow down our research area and define our research question. To answer it, the prototype named Slots-story(2nditeration) and Slots-memento(3rditeration) were designed and implemented, which focused on life story and memento story of the elderly respectively. While the 4thiteration aimed at facilitating intergenerational story sharing and sustainably. The above research iterations offer an example of how research prototypes supports to focus research area, and answer the research question in stages. We finally conclude with a discussion of insights on designing prototype for the non-tech-savvy elderly.