Written for the 2021 film of the same name – a remake of the 1997 Canadian thriller – "Cube" was inspired by a sense of anger Hoshino felt in the original.

Its instrumentation primarily consists of bass, organ, guitar, and programmed drums, drawing influence from alternative rock, punk, soul, and gospel.

Lyrically, it compares the world to an inescapable cube and includes references to the film, with later lines introducing a more hopeful message.

Hoshino promoted the song alongside the remake's lead actor Masaki Suda, appearing on each other's segments of the radio program All Night Nippon and co-starring in an interview released to film distributor Shochiku's YouTube channel.

It reached second place on both Oricon and Billboard's digital download charts, and held two consecutive weeks atop Plantech's airplay ranking.

[4]: 1 [6] The text includes links to the movie, such as in the final line "We're always gonna be stuck in this endless absurdity", which is adapted from a quote in the 1997 film.

Hoshino told Model Press that he was glad to have worked with Suda; though they previously co-starred as adversaries on the television drama MIU404  [ja] (2020), their characters rarely interacted.

[3][7] The production on "Cube" continues changes in Hoshino's style debuted with his previous singles "Create" and "Fushigi" (2020), taking use of electric keyboard and a digital audio workstation.

Hoshino enlisted the help of long-time collaborator and guitarist Ryosuke Nagaoka for arrangement of the chorus vocals, who completed the process in one day.

[5]: 1  He settled on a minimal instrumental line-up of drums, bass, organ, and electric guitar to fit his perception of a progressive and manic sound.

[5]: 1  He incorporated elements from punk and alternative rock such as a warped guitar, and on the drumming drew from 1960s to 70s soul music and the type of gospel he thought could be played in a countryside church.

Choreographer Mikiko, who previously worked with Hoshino on singles like "Sun" (2015), both directed and co-choreographed the song's music video in her directorial debut, which was premiered on October 20, 2021.

[7][15] In their two-way interview for Shochiku, Suda recalled that he couldn't understand what was happening around him during filming but thought the final result ended up with a feeling of mystery.

[10] Chihiro Ogawa for Rockin'On Japan called the first half of the beat unusual – "a restlessness that engulfs listeners in disorder" – but thought the sound progressed into a lighter style, highlighting the use of organ.

[6] Both critics likened the uneasy or unpredictable beat to "Create", with the Rhythm & Drums writer also tracing the style back to "Fushigi" and the Pop Virus single "Idea" (2018).