Limited research has explored how Korean pop (K-pop) fans respond to incongruent celebrity endorsements, where the celebrity’s image conflicts with the brand they endorse. This study, conducted with 525 consumers of Hallyu (Korean Wave), reveals that fans react angrily when a celebrity’s image does not align with the endorsed brand. Such anger significantly reduces their willingness to purchase products or services associated with these celebrities. The findings highlight the critical importance of aligning celebrities’ images with their endorsed brands to maintain fan support and achieve business success.