The United States of America has been in chaos ever since the emergence of D2s, an invasive species originating from a black meteorite that fell to Earth. A public decree banned citizens from playing any melodies, to prevent further casualties caused by the D2s' hatred for music—even now, in 2047, this prohibition is still in effect. Humanity's only form of defense against the D2s are Musicarts, young women representing pieces of classical music; and Conductors, the ones controlling them. Takt Asahina, an aloof piano prodigy, finds himself transformed into a Conductor following a spontaneous D2 attack. The same incident kills Anna Schneider's younger sister, Cosette, and brings Takt into contact with his Musicart, Destiny. Searching for a means of stabilizing the pact between themselves,