G.I.S.M. was a Japanese punk/metal band formed in Tokyo in 1981. Although the guitar style resembled heavy metal in many aspects, G.I.S.M. was one of the first Japanese hardcore bands, while at the same time drawing influence from the early industrial/avant-garde music scene—something uncommon in punk bands at that time.

The acronym G.I.S.M. has many different variations; they include: “Guerrilla Incendiary Sabotage Mutineer” (original), “God In The Schizoid Mind”, “Grand Imperialism Social Murder”, “Genocide Infanticide Suicide Menticide”, “Gay Individual Social Mean”, “Gothic Incest Sex Machine”, “Grubby Incest Stripper Mastitis”, “Gravity Impel Slaying Machine”, “Get Incinerated Sorrow Mass”, “Gore Impromptu Suicide Mine”, “Grim Iconic Sadistic Mantra” and “Gnostic Idiosyncrasy Sonic Militant”.