Eleven years after the launch of internet-connected augmented reality eyeglasses and visors, Yūko Okonogi relocates with her family to Daikoku City, the technological hub of the emerging half-virtual world. She joins her grandmother's "investigation agency," a group of children outfitted with virtual tools and powerful metatags. Yūko soon encounters Yūko Amasawa, a skilled hacker of the virtual realm, who is persistently trying to "unlock" the mystery of a computer virus originating from an inaccessible, corrupted space.