Rin and his friends, along with the rest of True Cross Academy Town, are in the midst of preparing for a festival that is celebrated only once every 11 years. While the barriers protecting the city from demon intrusions are being repaired, Rin and his twin brother Yukio are sent to the scene of an exorcism as reinforcements. Things take a turn for the worse and as they attempt to salvage their mission, they meet a mysterious young boy that may threaten everything that they know. Meanwhile, Cheng-Long Liu, a First Class Senior Exorcist from the Taiwan Branch, joins the 'simple' repair operation that forces his fate to cross with 'Satan's spawn', Rin. Written by ELEVEN ARTS

The story takes place in a alternate postwar period, in 1996, where Japan is divided. Hokkaido is ruled by the "Union" while Honshu and other southern islands are under US authority. A tall tower was built on Hokkaido, which could even be seen from Tokyo. In the summer of 1996, three middle-school students make a promise that they'll cross the border with a self-constructed plane and unravel the tower's secret, but their project was abandoned after the girl, Sayuri Sawatari, became mysteriously ill and transferred to Tokyo. Years later on the brink of another war Hiroki Fujisawa finds out that Sayuri had been in coma since then, and he asks Takuya Shirakawa to help him finding a way to wake her up.

As the world moves on from the war and technological advances bring changes to her life, Violet still hopes to see her lost commanding officer again.