After contacts with Takehisa Yumeji in 1909,[2] between 1910 and 1915, he studied oil painting and sculpture at the Tokyo School of Fine Arts (東京美術学校, Tōkyō Bijutsu Gakkō).

Onchi was also a book designer in the early days when it was impossible for sōsaku-hanga artists to survive by just doing creative prints.

[citation needed] In 1928 he joined with seven other sōsaku hanga artists to work on the 100 Views of New Tokyo series, to which he contributed thirteen prints.

"[3] In 1939, he founded the First Thursday Society (一木会, Ichimokukai), which was crucial to the postwar revival of the sōsaku-hanga movement.

He was more interested in expressing subjective emotions through abstract prints than in replicating images and forms in the objective world.

[citation needed]Onchi innovated by incorporating fabrics, string, paper blocks, fish fins, and leaves in his prints.

From around 1932, Onchi worked on the design of a number of books about photography published by Genkōsha (玄光社) and Ars.