After having a hot pot party with the spirits, Shido and the crew of the Fraxinus depart to meet a new spirit who appeared. Introducing herself as Natsumi, the spirit appears to be friendly to Shido at first, until she suddenly changes her behavior and without further explanation, declares that she will destroy Shido's life before making her leave. Back at school, Shido is surprised when his classmates and teacher accuse him of committing multiple offenses against them, until he learns that the true culprit is Natsumi, who disguised as him to destroy his reputation, but before Natsumi attacks Shido, Touka and Origami intervene and easily distinguish the true Shido from the false, forcing her to retreat. Some days later, Kotori approaches Shido with a letter from Natsumi containing pictures of twelve people close to him. According to the letter, Natsumi disguised herself as one of them and is challenging Shido to identify the imposter before all of them are disappeared.