As his father was frequently transferred, as a child Jinzai lived in many locations around Japan, the longest period of which was in Taiwan (then under Japanese rule).

Initially aspiring to become an architect, he was interested in poetry and French literature, but after enrolling in the Tokyo University of Foreign Studies, he changed to Russian instead.

After graduation, he worked briefly for the Hokkaido University library, then with the Tokyo Denki Nippo newspaper, before being hired by the Soviet trade office.

Jinzai had a very diverse output, ranging from historical novels, literary critiques, verse, and stage plays.

Jinzai relocated to Kamakura, Kanagawa prefecture in 1934, but moved back to Tokyo to be closer to his publisher and theater.