EGOIST was a Japanese music group consisting of vocalist chelly and composer/producer ryo of the band supercell. The band was formed in 2011 as a fictional band within the anime series “Guilty Crown,” and their music was used as the soundtrack for the show. However, after the anime ended, the band continued to produce music and release albums independently.

On August 2023, chelly announced that EGOIST will cease activities in October 2023.