Mephisto's amusement park is haunted by a child ghost so the Esquires are tasked to look for him. Rin encounters Amaimon, his and Mephisto's younger half-brother, who forces him to fight. Rin loses control and goes haywire, almost putting Shiemi in danger. One of the quieter Esquires defends Rin, causing Amaimon to retreat. This Esquire exposes herself to be not a student but a high-level Exorcist, Shura Kirigakure.