Despite the growing consensus on the potential of dynamic assessment (DA) in second language (L2) development, application of DA procedures to corrective feedback (CF) on L2 writing has received relatively little attention. Still more neglected has been the social-emotional outcomes of CF operationalized as DA procedures. The present study addressed this research gap by investigating two college-level Japanese-language learners' social-emotional responses to CF as mediation on L2 writing utilizing a case study approach. The learners participated in writing conferences in which they received CF as mediation. The data sources include semistructured interviews, stimulated recall interviews, and a focus group interview. Interview transcripts were analyzed qualitatively using NVivo for emerging themes. Findings suggest that CF as mediation engendered positive emotions intertwined with interpersonal factors, confidence, and motivation. Furthermore, the findings from the narrative analysis provide concrete examples of how positive emotions can expand the learner's zone of proximal development.