A certain book-loving woman in her thirties is reincarnated as the childhood version of "Yulia Jayos," a minor character in the world of the novel she was reading, after a traffic accident in her current life. However, in the novel, Yulia and her family are fated to be executed by the villain. Knowing the story's ending, Yulia decides to change the future before the villain can destroy the world. To do so, she chooses to participate in the villain's children's knight training program, "Agerisk." Eventually, Yulia finds the villain, Roziel, and tries to make contact. However, the actions taken by a minor character to save the world begin to steer the entire story in an unforeseen direction…!