He was born into a small landowning family in 1907 in Hiroshima, and given the name Nichiro Ishimura, which he later changed to Ai-Mitsu when he moved to Tokyo to pursue his career as an artist.
Born into a modest farming household in 1907 in Hiroshima, he was initially named Nichiro Ishimura but later adopted the alias Ai-Mitsu after relocating to Tokyo to focus on his artistic career.