This study analyzed the mechanism of twist ending narratives and examined readers’ cognitive and affective responses while reading short twist-ending stories. In narrative analysis of twist-ending stories, discourse structures were divided into two types of preceding events; one defined as bias-generating event, the other defined as concealment event. The bias–generating event increased readers’expectancy and made stories more enjoyable. The concealment event played a role in hiding the truth and secret of plot twist. The type of twist-ending narratives was defined according to the role of events concerned with the mechanism of organizing plot twist. In the empirical research, readers’ affective and cognitive responses were investigated. The mechanism of bias generation formulated readers’ false conception and led their attention to the wrong direction which interfered with expecting the result of preceding events. The mechanism of concealment made readers feel stories more mysterious and puzzling. This study attempted interdisciplinary approach of literary theory, media psychology, and cognitive science. The significance of this study is that the mechanism of twist ending narratives was demonstrated by readers’ affective and cognitive response model.