Commentators have noted how Dir en Grey have gained a significant international fanbase with vocals in Japanese. Kaoru said "when I was growing up, I listened to American bands. They were all singing in English and I had no idea what they were saying. But I still remember the excitement that I experienced. I know as a listener that our fans can connect to our music in the same way — even with the language barrier." When asked why they almost always use Japanese instead of English, which would give them more broad international appeal, he said that "We consider our music be a piece of art. [...] The language is part of that artwork." The guitarist explained that Kyo, who writes all of the lyrics, prefers "the sensitivities that Japanese language offers. There are expressions and nuances that can only be conveyed in Japanese; he values that." However, he noted that likewise there are some expressions that are only able to be shown in English, so they also plan to use English when they feel the need. The lyrics 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, last featuring on "Uroboros"), and several songs rely heavily on double entendres and other wordplay, often involving the multiple meanings of a kanji character.