A member of the Fluxus Group in New York, he has been exploring new forms of expression using the mail since he was in John Cage's class at Black Mountain College, where he started an art form called mail art and opened up a new field. His exchange with Jiro Yoshihara brought new ideas to the Gutai by presenting the concept that the exhibition of artwork is not limited to exhibitions, which later led to the use of the mail to introduce their work to people far away, beginning with the New Year's greeting cards. He was one of the first important overseas artists to contact Gutai, and in Issue 6 of Gutai, a letter and a work sent to Yoshihara from Ray Johnson were published. In later years, after Gutai disbanded, Shozo Shimamoto started mail art, but somewhere in his mind, the memory of this time must have remained.