[5][6] Ushio worked alongside movie director Naoko Yamada which had a very similar point of view when it came across the concept of the film and music.

[7] Kensuke Ushio described the movie as Shōya's story that deals about his contacts with other people and how treats them, which was a universal theme when it came to bring it out of context.

[4] Yamada, who was familiar with Ushio's music, contacted his management requesting his involvement in composing the soundtrack.

[4] The studio works ended when sound director Yuta Tsuruoka got the final musical concept and approved it.

[8] Ushio decided that he would use his identification codes as song names instead of renaming them in order to tell the listener their possible meanings.

Ushio stated the movie is about reaching the light, which is why the songs were played at the very end of the film.

[8] James Marsh of South China Morning Post wrote that the discordant sounding score by Ushio lays an unsettling layer on the complex sounding landscape of the film which brings the viewer nearer to Shōko Nishimiyas world's view.

[10] In a movie review at Anime News Network Kevin Cirugeda wrote that Kensuke Ushio and Naoko Yamada worked closely together on the soundtrack resulting – excluding the licensed "My Generation" by The Who – in gentle piano sounds, ambient sounds and pure silence.

There are no significant tracks instead the films as whole was described as a sensory experience where the sounds play as such of a role like the background music used in the movie.