Ay-O (born Takao Iijima in 1931) is a Japanese avant-garde artist internationally recognized for his vibrant, rainbow-colored works and his association with the Fluxus movement. Nicknamed the “Rainbow Artist,” Ay-O gained prominence for his joyful and tactile use of color, combining conceptual art with playful experimentation.

Born in Ibaraki Prefecture, Japan, Ay-O studied at Tokyo University of Education before joining the Demokrato Artists Association, where he connected with key figures in Japan’s postwar art scene. In the late 1950s, he moved to New York and became affiliated with Fluxus, an international network of artists known for its anti-commercial, intermedia art practices. Through Fluxus, Ay-O collaborated with artists such as George Maciunas, Yoko Ono, and Nam June Paik.

Ay-O is best known for his Rainbow Series, which he began in the 1960s. These works span paintings, prints, installations, and even tactile boxes, all characterized by gradations of bright, rainbow hues. His 1966 participation in the Venice Biennale with a rainbow-themed installation further solidified his international reputation.

Blending humor, sensory engagement, and a utopian idealism, Ay-O’s work consistently challenges the boundaries between art and life, and embodies his philosophy of inclusivity, color, and joy.