GISM ( also G.I.S.M.) were a hardcore band (with strong metal leanings) formed in Japan in the early 1980s. The acronym G.I.S.M. has never had a constant meaning attached to it. Variations include God In The Schizoid Mind, Guy In Suicide Mission, Guerilla Incendiary Sabotage Mutineer, and Gnostic Idiocyncracy Sonic Militant.
GISM were widely known for the extreme violence present in their lyrics, and live shows.