The plot (content or storyline of a story) may disappoint users who read review comments associated with items containing a story such as comics, novels, and movies. This paper proposes a new method for identifying sentences that include descriptions of the plot of the story. Conventional methods only use information based on the words contained in a target sentence, however, our new method uses contextual information in addition to word information. We identify contextual information by using the sentence location and the plot probability of surrounding sentences. An experiment showed that this method improved the accuracy with which plot-related information can be identified.