Nightmare are one of the more successful visual kei bands, able to tone down their X-Japan/Luna Sea worship and the predilection for extravagant attire that comes with the style. Thanks to that, and the careful crafting of their goth/hard rock infused with a healthy dose of pop-jazz, they managed to swiftly rise to the heights of the Japanese music industry, evidenced by their collaboration with some of the bigger anime series. The band was started in 2000 by Sakito and Hitsugi, both guitar players, who expanded the lineup with vocalist Yomi, bassist Ni~ya, and Ruka, the former drummer of Luinspear, and then had at it with full force. A flow of indie singles that issued forth in the next two-and-a-half years clicked with the public well enough and, coupled with several one-man (i.e. individual) tours by the bandmembers, got Nightmare a contract with Nippon Crown, who released their first major single "Believe" (number 24 on the charts), followed by the debut LP Ultimate Circus by the end of the 2003. Since 2001, the bandmembers also engaged in the "flipside band" project, Sendai Kamotsu, sporadically appearing both live and in the studio to play a different, mildly chaotic sort of music that included influences from samba to metal everything in between.
Nightmare followed their debut up with a steady working schedule, releasing full albums Libido (2004) and Anima (2006), which marked the band's shift from a harsher sound to a more varied and jazz-influenced one. In 2005 the band also got their own radio show, usually hosted by Yomi and Hitsugi, and switched to the Vap label. Their success gained Nightmare entry into the anime world in 2006, when the group's double A-side single "The World/Alumina" made it into the credits of the wildly popular anime series Death Note. 2006 marked an overall burst of recording activity for Nightmare, with the band releasing their fourth studio album The World Ruler, as well as a compilation of early tracks, a best-of CD, and two DVDs. Their relationship with the anime industry became quite steady at this point: in 2007, the single "Raison d'Etre" got picked for the Claymore series, and "Dirty" was used in Majin Tantei Nougami Neuro. In 2007 the band also debuted at the nation's most prestigious venue, the Budokan, before returning to the studio to record their fifth studio album, Killer Show, out in May 2008. In August, bassist Ni~ya collaborated with fellow J-rockers Penicillin on their single "Rainbow/Scream."
Nightmare's next album, 2009's Majestical Parade, continued to show their softer side, but the follow-up could not have been more different. Their special album Gianizm was released on January 1, 2010, on exactly the tenth anniversary of their formation. A compilation of re-recorded versions of all their "Gianizm" concept songs, it was a non-stop barrage of hard, heavy, brutal, dissonant, and nearly tuneless funk metal and hardcore punk, and came as a slap in the face to fans who had come to the band through their poppy anime theme tunes. Shortly thereafter (whether as a result of the album or not is impossible to say), the band left Vap and went to Avex, sometime home to other top-flight visual bands such as Megamasso, Kannivalism, and D. Their eponymous Avex debut, released in 2011, was their most rounded album to date, containing elements of both their poppy and heavy sides, but the 2013 follow-up, Scums, was heavier, less tuneful, and much more aggressive.