In a rural town undergoing revival through music, high school students Kanae and Sousuke meet none other than Beethoven and Mozart! Calling themselves Classicaloids, these mysterious two create a strange power through the music they play that makes stars fall from the sky and giant robots appear. Later, Bach, Chopin and Schubert also emerge as Classicaloids. What is the mystery behind the powers they possess? Are they humanity's friends or foes?