Kazuo Shiraga initially studied nihonga in Kyoto but was discontent with its traditional style and materials. He began experimenting with painting using his fingers, and found he preferred the thick tube-based oil paints to the thin ink-based paint of his studies. In 1952 he co-founded the Zero Society (Zero-kai) with Saburō Murakami and Akira Kanayama. Soon after that he joined Gutai Art Association. Gutai emerged out of a Japan torn apart by the atomic bombing of Hiroshima and Nagasaki, the loss of World War II and the American occupation of Japan. Postwar Japan was facing an identity crisis—a struggle between tradition and modernity that was reflected and expressed in the art of Gutai. The artists of Gutai were in the throes of an unimaginably new era. Jiro Yoshihara, a leader of the group, reacted by telling the group to 'make something that has never existed'. In his art, Shiraga reflected the emerging new sense of the relationship between body and earth, or an artist and his materials. In works such as Challenging Mud (1955) he wrestled with a mud mixture, in doing so forming it into sculptural and painterly shapes. While Yoshihara saw physical remnants of a performance as residue, Shiraga valued each part equally. Shiraga knew of Jackson Pollock and Abstract Expressionism, but sought something beyond what Abstract Expressionism could provide.