The war between humans and demons has raged on and spiraled since the beginning of life, where neither side can triumph over the other or backs down. In the city of Elimnea, daily encounters with demons are prominent and its citizens struggle with maintaining peace and tranquility.
Ever since she was a little girl, Serena has dreamed of the day that she could become an exorcist for CORA, an organization that defends humans against supernatural creatures. The day that her dream is finally realized, she befriends a fellow exorcist, Ethan, who helps her in achieving her goal. However, there is more to him than one may suspect, and he may hold the means of changing life for humans as they know it.