On June 2, 2021, Yoasobi was announced to be in charge of writing and singing a theme song for the play Moshi mo Inochi ga Egaketara (もしも命が描けたら), starring Kei Tanaka, Mario Kuroba, and Hijiri Kojima.

The play was written by Osamu Suzuki, a screenwriter who also wrote Tsuki Ōji, a based short story for the duo's song "Haruka".

Performed on August 12–22 at Tokyo Metropolitan Theatre, the story depicts a man who draws a picture as the time of life gradually decreases in order to share it with someone.

[2] The full-length version of "Moshi mo Inochi ga Egaketara" was played for the first time at Tokyo FM's Jump Up Melodies Top 20 on November 26.

[6] Yoasobi gave a debut performance of "Moshi mo Inochi ga Egaketara" on December 30, 2021, at the 63rd Japan Record Awards, alongside "Kaibutsu", and "Yasashii Suisei".