Mirror clairvoyant Nanaki Bekku sees future disasters in reflective surfaces but has always been powerless to stop them. Haunted by this trauma, she moves from the countryside to Tokyo hoping to escape the visions. On her first day in the city, a strange boy blocks a pedestrian crossing with a flimsy excuse, which causes a falling billboard to miss her and saves her life. The next day she discovers he is Banjou Kizaki, her new classmate and a notorious troublemaker whose eccentric behavior masks a desperate mission. Banjou carries a notebook filled with photographs of future accidents and catastrophes, and he has dedicated himself to breaking every prophecy it contains. The final page of his own notebook foretells his death at age twenty, and he believes that if he can shatter enough other prophecies, he can overwrite that fate. At first Nanaki resists his reckless methods, still convinced that the future cannot be changed. But witnessing Banjou throw himself into danger without being bound by fate moves her, and she decides to join his fight to destroy prophecies. Their partnership draws the attention of a third figure, the prophecy enforcer Mahoku Eitarou, who works to ensure that the predictions are fulfilled. This conflict ultimately leads Nanaki and Banjou toward the original source of all prophecies, the mysterious Cassandra Mask. In a final battle that spans the two-volume story, they confront the mask to uncover the shocking truth behind its power and to decide whether Banjou's prophesied death can truly be escaped.