Low participation of minority shareholders is a common phenomenon in corporate governance in China's A-share capital market, and online influencers play a crucial role in mobilizing them to exercise their rights. Drawing on narrative economics and resource-mobilization theory, this study adopts a netnographic approach and conducts online fieldwork on the collective rights exercise event of minority shareholders in COSCO, to explore how online influencers mobilize minority shareholders through narratives. The case analysis reveals that expertise, group identity, and networks constitute the core mobilization foundation of online influencers. By leveraging emotion-logic intertwined composite narratives, they activate minority shareholders'willingness to exercise their rights. Through cascade propagation, memetic diffusion, and resonance, the narratives are disseminated. With the external support of investor protection institutions and media coverage, online influencers effectively mobilize minority shareholders'resources such as attention, emotion, and voting rights, ultimately facilitating collective rights exercise. Further analysis indicates that the rights-exercise narratives trigger negative short-term market reactions, but promote the improvement of investor protection and the awakening of minority shareholder awareness in the long run. This study broadens the scope of participants in shareholder activism research and reveals the mechanisms of minority shareholder activism in the digital era.