"Circular forms" increasingly began to appear in the works of avant-garde painters in the Showa period. These distinct forms, such as circles in abstract paintings, figurative eyes, or holes, were, however, linked together by a common artistic approach. Many artists used these "circular forms" in their compositions as minimalist temporary subjects. This attitude can be compared to the circular scribbles produced by young children generally referred to in developmental psychology as "mandala". In other words, these artists used the unarticulated, blank canvas as an opportunity to experiment, and with each brushstroke they applied to the ground their individual self-expression naturally emerged. If one considers the parallels between early Showa avant-garde artists and the art of young children, then the artists. canvases, their exhibition spaces, and the art system that supported them are like the children's blank sheet of paper. The paintings from the early Showa period employing various kinds of circular forms reveal how the system that supported modern and contemporary art in Japan did not provide an open window out to the rest of the world, but was rather a straitjacket on artistic creativity.