Maeda Josaku was born in Toyama Prefecture and graduated from Musashino Art School in 1953. From 1953-57 he exhibited with the Freedom Art Association, a group of artists that organized exhibitions for its members. On a scholarship from the Free Cultural Association from 1958-63, Maeda lived in Paris and in 1958 he began work on a series of paintings based on Indian mandalas.

In 1961 Maeda won an award at the 6th Japan International Art Exhibition and in 1963 he won the grand prize in the same exhibition. Continuing his work on the mandala theme, Maeda traveled to India in 1971 and to Iran and Iraq in 1973. One-man exhibitions of his work have been held in 1955-56 at Gallery Takemiya in Tokyo, in 1957 at Gallery Sato in Tokyo, in 1958 at Gallery Daiwa in Toyama, in 1963 at the Tokyo Gallery and Gallery Aoki in Tokyo, and in Paris in 1965 at Galerie Lambert and Galerie Karl Flinker.