All lyrics are written by Kyo and deal with subjects such as society and mass media, as well as sexual obsessions and love, usually with negative implications. The vocabulary varies from subtle to explicit, though the use of profanity has greatly decreased as the band matured, and several songs rely heavily on double entendres and other wordplay, often involving the multiple meanings of a kanji character.
Kyo's singing is considered a pivotal aspect of the band, and he has gained recognition for his distinctive vocal work and for his large range and versatility, being able to "howl, croon, emote cleanly, scream, shriek, growl, bellow, and make nearly inhuman sounds".
Originally a visual kei band, the band has opted for less dramatic attire in recent years.
Numerous stylistic changes have made the genre of their music difficult to determine, though it is generally considered to be a form of metal.
As of 2014, they have recorded nine full-length records with a lineup consistent since its inception.