In the capital of Xiao lives one of the finest exorcists the world has ever known—a girl of seventeen named Gekki Tou. Despite hailing from a line of distinguished exorcists, Gekki travels around the country to help a wide variety of people deal with malignant spirits alongside her surly fiancé and bodyguard, Reiyou Hou. One day, she receives a request from a member of the wealthy Kohou family who claims he’s being haunted by the spirit of a recently deceased cousin. But as soon as they begin their investigation, the client dies in a suspicious accident. When more members of the Kohou family succumb to supernatural mishaps, it becomes clear they have no ordinary case on their hands. But does this pair of opposites have what it takes to get to the bottom of it before the Kohou fall to ruin?