The Gutai group (具体； means "tangible; material; concrete") was an artistic movement and association of artists founded (according to most sources) by Jiro Yoshihara in Japan in 1954. According to the official website of Shozo Shimamoto, Shimamoto and Yoshihara founded Gutai together in 1954, and it was Shimamoto who suggested the name Gutai, which means (again, according to this source) “concrete” (as opposed to abstract/theoretical) .
The Gutai Manifesto
Yoshihara wrote the manifesto for the Gutai group in 1956. The full text of the "Gutai Manifesto" is available in English at the website of Japan's Ashiya City Museum of Art & History . Among its preoccupations, the manifesto expresses a fascination with the beauty that arises when things become damaged or decayed. The process of damage or destruction is celebrated as a way of revealing the inner "life" of a given material or object:
"Yet what is interesting in this respect is the novel beauty to be found in works of art and architecture of the past which have changed their appearance due to the damage of time or destruction by disasters in the course of the centuries. This is described as the beauty of decay, but is it not perhaps that beauty which material assumes when it is freed from artificial make-up and reveals its original characteristics? The fact that the ruins receive us warmly and kindly after all, and that they attract us with their cracks and flaking surfaces, could this not really be a sign of the material taking revenge, having recaptured its original life?...." 
In addition to Yoshihara and Shimamoto, members of the Gutai group included Sadamasa Motonaga fr:Sadamasa Motonaga, Atsuko Tanaka, Akira Kanayama, and others. A formative influence on the later Fluxus movement, the group was also associated with certain European (particularly French) art world figures such as Georges Mathieu and Michel Tapié, and with tachisme ("art informel"). According to the Tate Gallery's online art glossary, Gutai artists also "created a series of striking works anticipating later Happenings and Performance and Conceptual art."  Gutai artists also created works that would now be called installations, inspiring the work of non-Japanese artists such as Allan Kaprow and Conrad Bo, and leading to the later Fluxus network.
The Tate article records that "the group dissolved in 1972 following the death of Yoshihara."
Gutai at the Biennale di Venezia 2009
- Jiro Yoshihara
- Shozo Shimamoto
- Atsuko Tanaka (artist)
- Kazuo Shiraga
- Installation art
- Georges Mathieu
- Michel Tapié
- Françoise Bonnefoy; Sarah Clément; Isabelle Sauvage; Galerie nationale du jeu de paume (France). Gutai (Paris : Galerie nationale du jeu de paume : Réunion des musées nationaux, 1999) ISBN 2-908901-68-4 9782908901689
- Alexandra Munroe; Yokohama Bijutsukan.; Solomon R. Guggenheim Museum.; San Francisco Museum of Modern Art. Japanese art after 1945 : scream against the sky'' [= 戦後日本の前衛美術空へ叫び /] (New York : H.N. Abrams, 1994) ISBN 0-8109-3512-0 9780810935129 [contents include "Nam June Paik -- To challenge the mid-summer sun : the Gutai group"]
- Michel Tapié. L'aventure informelle (according to Worldcat "Details" information: "Other Titles: Gutaï.") (Nishinomiya, Japan, S. Shimamoto, 1957) OCLC 1194658
- Tiampo, Ming. Gutai and Informel Post-war art in Japan and France, 1945--1965. (Worldcat link: ) (Dissertation Abstracts International, 65-01A) ISBN 0-496-66047-0 9780496660476
- Jirō Yoshihara; Shōzō Shimamoto; Michel Tapié; Gutai Bijutsu Kyōkai. Gutai [= 具体] (具体美術協会, Nishinomiya-shi : Gutai Bijutsu Kyōkai, 1955-1965) [Japanese : Serial Publication : Periodical] OCLC 53194339 [Worldcat "Other titles" information: Gutai art exhibition, Aventure informelle, International art of a new era, U.S.A., Japan, Europe, International Sky Festival, Osaka, 1960]
- Mattijs Visser; Gutai. Mal communication; Making Worlds, Exhibition catalog 53rd International Art Exhibition, La Biennale di Venezia 2009; ISBN 978-88-317-9696
- “ZERO, Internationale Künstler Avantgarde“, published by Museum Kunst Palast and Cantz, with essays by Jean-Hubert Martin, Valerie Hilling, Catherine Millet and Mattijs Visser, Düsseldorf/Ostfildern 2006 ISBN 3-9809060-4-3
- Ming Tampo, Guest Curator, "Under Each Other's Spell": The Gutai and New York. Catalogue © 2009 The Stony Brook Foundation, Inc.
- Tiampo, Ming. Gutai: Decentering Modernism. (Chicago : University of Chicago Press, 2010) ISBN 0-226-80165-9 978-0-226-80165-0
- The Gutai Archive (Japanese)
- Material on Shimamoto
- Fluxusgenova.org historical essay on Fluxus, mentioning formative influence of "Gutaj" [sic] group
- UNESCO biographical information on Atsuko Tanaka: "...Performances featuring different costumes were the main characteristic of her work with the Gutaj Group."
- Tate Gallery: article on Gutai
- Website of the Ashiya City Museum of Art & History
- Complete text of the Gutai Manifesto (provided in English translation by the Ashiya City Museum website)
- ZERO foundation
- ZERO group
- Venice Biennaleit:Gutai