Earth is full of unknown apparitions, some might be harmless, but other are real monsters. These are known as ‘Kegare’ -or impuriries-, and must be destroyed by exorcists.
One day in Tokyo, Rokuro Enmadou is busy asking one of her classmates to date him, but he is immediately rejected. Rokuro seems to have experience, and once he finds himself in troubles he tries to escape, bumping with Mayura Otomi, an old friend.
It seems Rokuro is preparing himself for the worse every time. And Mayura tells him to stop going after every random girl he encounters.
But he is a stubborn guy, and believes that love will change his life forever. Unfortunately, he seems totally unreliable, if not scary.
On the other hand, we find Benio Adashino, who has been summoned from Kyoto. She seeks nothing but perfection, and she has to be exactly that. After all, she has trained all her life to become an exorcist.
As she travels, something is wrong, suddenly several Kegare attack her train and she must act before they hurt someone. Without reluctance, she performs her exorcism.
Meanwhile, something similar occurs in Tokyo, but Rokuro doesn’t want to get involved in anything related to Keegare. He is a talented boy, but is retrained by memories from his past.
Benio fights and prevails, ending up exhausted. As she returns to our realm, she appears in front of Rokuro, about to fall down into a river. He jumps to save her, and both end up soaked.
Without many words, Benio asks Rokuro for directions, and they end up lost and hungry in the city. After a snack, they proceed with their journey, just to find more difficulties.
Several Kegare attack, and without noticing, they end up battling a strong impurity. Rokuro can’t understand her determination and will to fight. But ends up taking action against his will.