Midnight Grand Orchestra is a Japanese musical project consisting of Japanese singer Hoshimachi Suisei and producer Taku Inoue. Formed in 2022 following multiple successful collaborations between Hoshimachi and Inoue, Midnight Grand Orchestra released their first two mini-albums, Overture and Starpeggio, in 2022 and 2023 respectively.
Prior to the founding of Midnight Grand Orchestra, members Hoshimachi Suisei and Taku Inoue had established a working relationship, with Hoshimachi appearing on Inoue's debut single "3:12" and Inoue in turn producing "Stellar Stellar", the first track on Hoshimachi's debut album Still Still Stellar. On 31 March 2022, Hoshimachi and Inoue would announce Midnight Grand Orchestra's founding following a teaser shown during an online live performance for Hoshimachi's fourth anniversary; the project's debut single, "SOS", would be released on 13 April. On 28 April, the project announced its debut mini-album Overture for release on 27 July. Following the reveal of a crossfade video previewing the mini-album's tracklist, "Highway" was released as a promotional single on 17 July. Upon its release, Overture received critical acclaim and modest commercial success, debuting in the top 10 on the Oricon and Billboard charts. Midnight Grand Orchestra would further promote Overture following its release with a virtual live concert of the same name on 20 August.