國學院大學
Yamaguchi was born in the Azabu district of Tokyo to a working-class family. He was forced to support himself through college, attending the Kokugakuin University. After graduation, he went to work for the publishing company Kawade Shobō, but that company went bankrupt a couple of years later. He then found employment as the editor of a wine magazine published by Kotobukiya (the forerunner of Suntory); his colleagues at the same magazine included Kaikō Ken and Yanagihara Ryōhei. The advertising campaign he mounted popularized Hawaii as a tourist destination as well as promoting Suntory whiskey.