Ōba was born on 28 February 1910, in Aoyama, Akasaka-ku, Tokyo.

[1] After graduating from Keio University's Department of Japanese Studies, Ōba started working at Shochiku.

[2] In 1953, Ōba made Kazuo Kikuta's radio drama Kimi no na ha aired on NHK into a movie, which became a major hit.

Kimi no na ha continued as a movie trilogy until 1954.

In his later years, he taught at the Japan Institute of the Moving Image.