|Years active||1981–2002, 2016-Present|
|Members||Sakevi Yokoyama (vocals)|
Kiichi Takahashi (bass)
Ironfist Tatsushima (drums)
|Past members||Kannon "Cloudy" (bass)|
Randy Uchida (guitar)
Souichi Hisatake (guitar)
G.I.S.M. (ギズム Gizumu) is a Japanese hardcore punk band formed in Tokyo in 1981. Even though the guitar style resembled heavy metal in many aspects, GISM 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 GISM 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", "Gore Impromptu Suicide Mine", "Grim Iconic Sadistic Mantra" and "Gnostic Idiosyncrasy Sonic Militant".
GISM has attained a cult status in the international punk scene, duly for their unique blend of heavy metal and hardcore punk. Roadrunner Records ranked Sakevi Yokoyama No. 49 out of 50 of The Greatest Metal Frontmen of All Time.
In 1984, GISM released their first album titled 'Detestation' on Dogma Records. . The album has been applauded for having unique vocals and a guitar style that was very uncommon in hardcore punk.
'M.A.N.', or 'Military Affairs Neurotic' , was released in 1987 on Beast Arts Records. The album was quite a departure from the 'Detestation' album, putting more emphasis on a slower, metal style of music compared to the hardcore punk sound of the previous release.
GISM released their last album on compact disc titled 'SoniCRIME TheRapy' in 2001 . The band featured Kiichi Takahashi on bass and Ironfist Tatsushima on drums. Guitarist Randy Uchida died from cancer on February 10, 2001, shortly after the release of the album. . GISM played two shows in Tokyo in honor of Randy Uchida, and then broke up.
In 2002, GISM made the cover of Burst Magazine (issue No. 49), an underground Japanese magazine.
GISM performed in the Netherlands on April 15, 2016 at Lee Dorian's Roadburn event. It was their first performance after a 13-year hiatus, along with being their first show outside of Japan. 
Members and other projects
Sakevi Yokoyama continues to make collage art with his own clothing brand "stlTH", which makes T-shirt designs. . In 1987, he made a cameo appearance in the Japanese film "Robinson's Garden". In the movie, he attacks a Rastafarian man for teaching children spirituality. This film is the only documentation of his "acting" career . In 2004, Sakevi released a solo album titled 'The War' under the name S.K.V.. In 2006, he designed the artwork for World Burns To Death's album titled Totalitarian Sodomy.
Randy Uchida (guitarist) & Hiroshima (original drummer) played with Ronny Wakamats & Michel Hammer in a side project called R.U.G. (Randy Uchida Group), which released one vinyl EP titled “Deathly Fighter” in 1984. Uchida died in 2001 of cancer.
Cloudy (original bassist) played bass for female-fronted speed metal band Front Guerrilla, which released an EP titled Fight Back in 1986.
Ironfist Tatushima (drummer) continues to play in the bands Die You Bastard! and Crow, which he had been playing with prior to GISM.
During the mid 80's, Sakevi published a Japanese punkzine titled P.O.W. The acronym of P.O.W. initially stood for Punk On Wave, but then changed to Performance Of War for the third, final issue. The magazine promoted local punk bands from the Tokyo scene at the time. Sakevi also personally interviewed the Tokyo Medical Examiners Office, wrote the P.L.O., and wrote prisoners of war from Anti Japanese Armed Fronts by asking them all their opinions on death, included vivid instructions on different ways to kill people and showed vivid drawings on how ABC weapons are made with images of their horrific consequences. John Duncan, the guest-editor for the magazine, stated in the introduction of the third issue that Sakevi attacked a salaryman for staring with a makeshift flamethrower on a Tokyo commuter train, subsequently landing him in prison.
- "Outsider" LP (1982, City Rocker) Tracks: "Incest", "Gash, Bite, Snatch", "AAHB"
- "Great Punk Hits" LP (1983, Japan Records) Tracks: "Death Exclamations", "Fire"
- "Hardcore Unlawful Assembly" LP (1984, AA records) Tracks: "Still Alive", "Nervous Corps"
- "International P.E.A.C.E. Benefit Compilation" 2xLP (1984, R Radical records) Track: "Endless Blockads for the Pussyfooter"
- "The Punx" Cassette Tape (1985, JICC)  Tracks: "Shoot to Kill (for epileptic soldier)", "GISM"
- "Determination" (2015) Beast Arts
- "Performance" (1985) Beast Arts 
- "BOOTLEG 1986" (1986) Beast Arts
- "Gay Individual Social Mean - Subj & Egos, chopped" (1995) Beast Arts 
- "+R, Regicide Reverberation" (2002) Beast Arts
- "GISM". Spirit of Metal. Retrieved 13 June 2019.
- 別冊宝島 ROCK FILE Vol.5 1989 特別版 日本ロックバンド完全事典. JICC出版局. 1989. p. 74.
- KFTH - Outsider Compilation LP