Terminology[edit]

The Japanese term denpa (電波, "electromagnetic waves") originally arose in the 1990s to describe quirky individuals who often daydream and live in their personal fantasies, and was derived from the Fukagawa Street murders in 1981. The assailant, Kawamata Gunji (川俣軍司), was using illicit substances when he slashed random bystanders in broad daylight, killing two housewives and two toddlers and injuring many others. When confronted in court, he explained that electromagnetic waves were telling him to kill people, and pleaded insanity.^[5]


By the early 1990s, the term denpa began to appear throughout music and literature, and the phrase denpa-kei (電波系) was used to refer to delusional, creepy people or crazed lunatics as a derogatory euphemism, based on the idea that such people could hear voices, see things and communicate through telepathy as a result of electromagnetic waves. Examples of such usage at the time include songs by Japanese metal band Kinniku Shōjo Tai, which made references to the murder incident.^[4]


In regards to music, the term obtained a negative connotation, and was mainly associated with music that was considered creepy and had incomprehensible lyrics, often of otaku origin. Since otaku were often seen as strange people who behaved differently from the rest of society, denpa became widely associated with otaku culture in Japan and the Akihabara scene. Eventually, the term denpa began to encompass anyone who seemed quirky or out of tune with reality, as if these people were being hypnotized or controlled by electromagnetic waves. As time progressed, the denpa categorization of music began to take form, and such music became popular amongst otaku circles as a niche interest separate from the mainstream.^[3][4]