In *Ao no Exorcist*, Rin Okumura, a seemingly ordinary teenager, discovers he is the son of Satan, who is unable to find a suitable host to possess and thus sends his son to conquer the human world, Assiah. When demons attack Rin, he learns of his demonic heritage and his father’s plans. Refusing to join Satan, Rin decides to train as an exorcist to protect Assiah. Alongside his brother Yukio, Rin vows to fight against his demonic lineage and defend the human world from his father’s destructive intentions, all while struggling with his own identity.