Despite the widespread applications of robots in education, fewer attempts have been made to how robots help middle school students in English-as-a-foreign-language (EFL) contexts to tell stories, let alone the probe into student emotions. This mixed-methods study, therefore, aimed to address these concerns by focusing on digital storytelling outcomes, positive/negative affect, and learner perceptions as the result of different presentation modes (robot-assisted versus PowerPoint-assisted). With 52 third-grade middle school students from two intact classes in a junior high school in Central Taiwan, the results from multiple data sources (pre-/posttests, an emotion questionnaire, and interview) revealed the benefits of both presentation modes, yet the robot-assisted mode was more advantageous in contributing to higher storytelling outcomes and more positive emotions. Despite the positive emotions experienced in both presentation modes, the results of the negative emotions were more mixed, as the students in both groups highlighted feeling scared and afraid in digital storytelling preparation and presentation. Suggestions based on the results of the study are provided.