From the beginning, one of the features of the band was a harsh sound and lyrics dealing with decadence and destruction, war, peace, isolation, love and death.

It was only after their first album Ningen Program got released on Speedstar Records, that they found a new bassist, Okamine Koushu, though he wasn't immediately made a full-time member.

As the band was becoming increasingly popular, they were asked to provide music for 2 movies: Kiyoshi Kurosawa's Bright Future and Kazuaki Kiriya's Casshern, releasing the album Ikiru Sainou in between them.

Their 16th major single release, Wana, was used as the first ending theme to the 2007 anime series Mobile Suit Gundam 00.

The song "Blade" by The Back Horn is used as the entrance music for Japanese professional wrestlers and mixed martial arts fighters Yukio Sakaguchi and Hikaru Sato.