This project investigates the design process of a straightforward, user-friendly interface that enables cooperative storytelling between a person with dementia and a family member, through the mediation of a social robot. Due to ethical constraints, evaluation was conducted only with a medical specialist and HCI students. Low cognitive load, sequential navigation, and multimodal visuals are given top priority in the final prototype. Working without direct user input and striking a balance between functionality and simplicity were two major obstacles. The project contributes to the development of supportive, dementia-friendly human-robot interfaces and provides a basis for future testing with individuals who have dementia.