Following a short period of military service in 1939 and through the early postwar years, he was involved in a series of collectives that sought to transcend the traditional aesthetic values in not just ceramics but also in a range of visual media.
Inspired in part by Isamu Noguchi's work in Japan in the early 1950s, which used ceramic materials to create modern abstract forms, Yagi and other members debuted so-called obuje-yaki ("kiln-fired objet "), or pottery with no functional purpose.
Yagi also introduced other experimental ceramic methods later in his career, such as burnishing his pottery objects black (so-called kokutō).
[3] After graduating from university, Yagi became a trainee at the Kokuritsu Tōjiki Jikenjō (National Ceramic Research Institute), which had been run by the Ministry of Agriculture and Commerce since 1920.
Numata was trained at the French porcelain manufactory in Sèvres and spent time in Auguste Rodin's studio, learning the art of ceramic sculpture.
Working against traditional aesthetics, the group explored avant-garde European trends in painting by Wassily Kandinsky, Surrealist artists, and the Bauhaus.
[9] In 1948, Yagi and his colleagues Osamu Suzuki, Hikaru Yamada, Yoshisuke Matsui, and Tetsuo Kano from the Seinen Sakutōka Shudan established the Sōdeisha ("Crawling through Mud Association"), an avant-garde ceramic arts group.
[7] Their manifesto drew from Surrealist language to declare its radical goals for ceramics, proclaiming: "We are united not to provide a 'warm bed of dreams', but to come to terms with our existence in broad daylight.
Unlike juried salons, Sōdeisha exhibitions did not distinguish between fine art and pottery, blurring the boundary as reflected in their works.
[12] In 1950, Yagi received early international acclaim when several of his works were included in an exhibition at The Museum of Modern Art in New York, Japanese Household Objects.
[15] His ability to create sculpture with clay as a synthesis of Japanese and Western aesthetics encouraged Yagi's own aspirations to push ceramics in new directions.
However, unlike Noguchi who was merely using clay as a medium, Yagi did not aspire to completely destroy the ceramic tradition in Japan – rather, he intended to push that heritage to its limits with new types of pottery.
By rejecting the functionality of the ceramic vessel, Yagi's work effectively opened up a new genre in the Japanese pottery world: the so-called obuje-yaki ("kiln-fired objet ").
[27] By the late 1940s, Yagi was already deeply influenced by images of Pablo Picasso's ceramics, particularly by the works' capacity to act both as a vessel and as a medium for representation.
Although ceramics were originally excluded from the Nitten exhibition, by Yagi's lifetime they were included and these works were gradually losing any daily functionality.
Obuje-yaki ("kiln-fired objet ") describes the most radical challenge to the separation of pottery from sculpture, in that the works are created with clay and fired in a kiln, but have no function and are appreciated primarily for their visual form.
[32] The work is made up of a large ring of clay that stands vertically on a number of small, pipe-like legs that recall the eponymous cockroach.
Yagi's work with obuje-yaki can be seen as part of a reaction again mingei (folk art) ceramics and the craft movement, which was inextricably linked to the nationalist ideologies driving Japanese militarism of the 1930s and 1940s.
[38] Yagi's teaching position at Kyoto City University of the Arts helped him pass on his knowledge and innovative approach to ceramics to many protégés.