Mio, a high school girl born into a family of kōshi—shamans who exorcise malevolent spirits—has been strictly forbidden from ever leaving her hometown in Nagano. Yet one day, defying her family’s orders, she secretly sets off for Kyoto. There, just as she is about to be attacked by an evil spirit, a mysterious boy named Takara comes to her rescue. But for some reason… he already seems to know who Mio is—!? A fateful encounter entwines a girl bound by her lineage and a boy who carries secrets of his own.