Jinzai was born in
Tokyo; his father was an official in the
Home Ministry. 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). In 1911, while in Taiwan, his father contracted
malaria and died in 1912. Jinzai was then raised by his maternal aunt. While in junior high school, he met
Michio Takeyama, and in high school he met
Tatsuo Hori, both of whom became his lifelong friends. 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. While still a student, he co-founded the
literary magazine Hoki ("Broom") with Takeyama Michio and Hori Tatsuo. The magazine gave him a foundation to publish his own plays, poems and translations of foreign literature. 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. In 1932, he decided to work as an author full-time. ==Literary career==