Many years ago, the last remnants of humanity were forced to retreat behind the towering walls of a fortified city to escape the massive, man-eating Titans that roamed the land outside their fortress. Only the heroic members of the Scouting Legion dared to stray beyond the safety of the walls – but even those brave warriors seldom returned alive. Those within the city clung to the illusion of a peaceful existence until the day that dream was shattered, and their slim chance at survival was reduced to one horrifying choice: kill – or be devoured!
Humans live in the world of Assiah, demons in Gehenna. The two dimensions are not meant to interfere with each other, but demons still possess creatures in Assiah in spite of this. The humans who can fight these demons are known as exorcists. Rin Okumura is a boy who bears the curse of being Satan's illegitimate son. His foster father sacrificed himself to save him from demons. To avenge his foster father's death as well as to prove himself, Rin decides to follow the path of an exorcist and defeat his own father, Satan. To hone his raw skills, Rin enters True Cross Academy to train with other exorcist candidates.
Nicknamed "Sadako" for her spooky appearance, high schooler Sawako begins to break out of her shell when she befriends popular boy Kazehaya.
