They are part of Sony Music Entertainment Japan's Palm Beach record label.
The members of Jinn all attended the same high school, and formed the band in Tokyo in the summer of 2003.
In March 2004, the band recorded a demo CD, 0~Zero~ (0～ゼロ～), with 500 copies selling out quickly.
In August 2006, the single Raion (雷音) was released, which was featured as the final opening theme to the Blood+ anime series.
In 2007, Jinn performed the second opening theme to the Sunrise anime series Code Geass: Lelouch of the Rebellion, Kaidoku Funō (解読不能), which was released on January 31, 2007.