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.

In 1934 he married Kie, a teacher of the deaf who helped support him through his struggles as an artist.

His most famous work is "Landscape with an Eye" (1938), currently held in the collection of the National Museum of Modern Art, Tokyo.

In 1944 he was conscripted and sent to China in the months after the war, where he died of a fever, possibly due to malaria and dysentery, on the outskirts of Shanghai.

In March - May 2007, a retrospective exhibition commemorating the 100th anniversary of Aimitsu's birthday was held at the National Museum of Modern Art, Tokyo.