Ay-O (b. 1931, Ibaraki Prefecture, Japan) is an Japanese artist associated with Fluxus. He began his artistic career at the Demokrato Artist Association in Osaka before moving to New York City in the early 1960s. He is known for his tactile “Finger Boxes” and for his performance events when he was active in Fluxus, collaborating with fellow Fluxus artists George Maciunas, Emmett Williams, Dick Higgins and Nam June Paik. Ay-O represented Japan at the Venice Biennale in 1966 and at the São Paulo Biennale in 1971. Major retrospectives of his work were organized by the Fukui Art Museum in 2006, which occasioned the publication of Over the Rainbow: Ay-o Retrospective 1950-2006. In 2012 a similar retrospective was organized by the Museum of Contemporary Art Tokyo and traveled to various locations in Japan. His work was featured in the group show Tokyo 1955-1970: A New Avant Garde at the Museum of Modern Art, New York (2012).