In the anime, episodes 1 to 10 explore the relationship between humans and spirits in the world of Polyphonica. The last two episodes Commandia focus on connecting the two types of creatures. "Apocrypha" is performed by Eufonius as the opening theme. "Concordia" is performed by Kukui as the ending theme.
On the continent of Polyphonica, spirits materialize in the world, surviving on the music play human beings, and living with them. While the spirits do not appear often, some spirits have enough power to materialize in human or animal forms and live with humans.