|Native name||赤瀬川 原平|
March 27, 1937
Yokohama, Kanagawa, Japan
|Other names||Katsuhiko Otsuji|
|Occupation||Conceptual artist, photographer, essayist, short story writer|
Genpei Akasegawa (赤瀬川 原平 Akasegawa Genpei ) is a pseudonym of Japanese artist Katsuhiko Akasegawa (赤瀬川 克彦 Akasegawa Katsuhiko ) (born March 27, 1937 in Yokohama). He used another pen name Katsuhiko Otsuji (尾辻 克彦 Otsuji Katsuhiko ) for literary works.
During the 1950s and 1960s, Akasegawa became involved within the Neo-Dada movement, along with Ushio Shinohara, Shusaku Arakawa, and Masanobu Yoshimura. He formed the Hi-Red Center with Jiro Takamatsu and Natsuyuki Nakanishi during this time, which was a group of artists that presented their works as a collective in Japan; they performed happenings within the Hi-Red Center. Akasegawa was also associated with the avant-garde.
In 1970s he used the idea of Hyper-Art (chōgeijutsu), an ordinary but useless street object that happened to look like a conceptual artwork. He called such things Tomasons, (named for Yomiuri Giants outfielder Gary Thomasson) and published photographs of them first within the magazine Shashin Jidai and later within books.
As "Katsuhiko Otsuji," he received the Akutagawa Prize in 1981 for his short story, "Chichi ga kieta". Akasegawa is known for many humorous essays, and his 1998 book Rōjinryoku was a major hit.
Akasegawa is fond of old (used) cameras, especially Leicas, and since 1992, he has joined Yutaka Takanashi and Yūtokutaishi Akiyama in the photographers' group Raika Dōmei, which has held numerous exhibitions.
"Thousand-yen bill incident" 
In January 1963, Akasegawa sent out invitations to a solo exhibition at a gallery in Tokyo. The announcement was delivered to several close friends in a cash envelope that was mailed through the postal service. The announcement itself was a 1,000-yen note reproduced in monochromatic colors on the front, with relevant information regarding the exhibit on the back. He produced four more during the next year.
In January 1964, his 1,000-yen note partial reproductions became noticed by the police and he was indicted for creating imitations of banknotes stemming from the 1894 Law Controlling the Imitation of Currency and Securities. The language of the law was quite vague, prohibiting any manufacture or sale of objects with an exterior front that may “be confused for currency or securities”. In August 1966, he went on trial for what was dubbed the "Thousand-Yen Bill Incident". In June 1967, he was found guilty with three months suspended sentence. He appealed twice. The decision was upheld in 1970.
- Obuje o motta musansha (オブジェを持った無産者). Tokyo: Gendai Shisōsha, 1970.
- Tuihō sareta yajiuma (追放された野次馬). Tokyo: Gendai Hyōronsha, 1972.
- Sakura gahō gekidō no sen nihyaku gojū ichi (桜画報・激動の千二百五十日). Tokyo: Seirindō, 1974.
- Yume dorobō: Suimin hakubutsushi (夢泥棒：睡眠博物誌). Tokyo: Gakugei Shorin, 1975.
- Chōgeijutsu Tomason (超芸術トマソン). Tokyo: Byakuya Shobō, 1985. Revised: Tokyo: Chikuma Shobō, 1987. ISBN 4-480-02189-2. English translation: Hyperart: Thomasson. New York: Kaya Press, 2010. ISBN 978-1-885030-46-7.
- Tōkyō mikisā keikaku (東京ミキサー計画). Tokyo: Parco, 1984. Reissue: Tokyo: Chikuma Shobō, 1994. ISBN 4-480-02935-4.
- Rōjinryoku (老人力). Tokyo: Chikuma Shobō, 1998, ISBN 978-4-480-81606-1. Reissue: Chikuma Shobō, 2001, ISBN 978-4-480-03671-1.
- Tomii, Reiko. "Guilty Verdict: Akasegawa Genpei and the 1000-Yen-Note Trial." 1997. Session 179: A Public Passionately Concerned with Itself: Japan's Public Sphere in the 1960s. 6 Nov. 2006.
- Marotti, William A. "Simulacra and subversion in the everyday: Akasegawa Genpei's 1000-yen copy, critical art, and the State." Postcolonial Studies: Culture, Politics, Economy 4.2 (July 2001): 211-239.
- Akasegawa, Genpei (1970). Obuje o motta musansha (in Japanese). Tokyo: Gendai Shisōsha.
- Akasegawa, Genpei (1994). Tōkyō mikisā keikaku (in Japanese). Tokyo: Chikuma Shobō.