Yano and Sano were originally going to work on the score together, with Yano handling the orchestral segments and Sano in charge of percussion and bass. Take wanted the soundtrack to stand out, but when Sano added together their two styles of music, he negatively compared the result to a song from Japanese variety show Nanikore Chin Hyakkei. Sano was so distressed that he insisted Yano handle all aspects of the music. The soundtrack and soundscape were created using 5.1 surround sound, which Sano found to be a mixed experience. While this enabled a wider range and depth of sounds, it also made coordination and balance more difficult. Despite the difficulties, he found the resultant effect superior to the two-channel sound of his previous projects. The theme song "The Vanishing Sky" was composed by Yano and arranged by Sano, with lyrics and vocals performed in English by Asako Yoshihiro.
