For centuries, terrifying creatures—known as "Kegare"—from the parallel realm Magano have wreaked havoc throughout Japan. The brave men and women resisting their onslaught are secretive exorcists whose one and only goal is to eradicate all the Kegare.

In the present day, 14-year-old Rokuro Enmadou is a talented and powerful exorcist. However, a tragic event in the past caused him to resent exorcists and give up his dream of becoming the strongest. In stark contrast to him, Benio Adashino is a beautiful and prodigious exorcist of the same age who carries the hopes and dreams of all people.

These two teenagers, despite their differences, are the prophesied "Twin Star Exorcists": the two people destined to give birth to the Miko—the exorcist who will vanquish the Kegare and cleanse the world of all impurities. But as the adolescents are both far from maturity, let alone adulthood, only hardships and trials await the unlikely heroes.