Born in Niihama, Ehime, Shikoku, in 1884, Shinji Sogo graduated from the Faculty of Law at Tokyo Imperial University in 1909, and joined the Railway Agency.

While at the South Manchuria Railway, he became closely connected with Kwantung Army officer Ishiwara Kanji, the key force behind the Manchurian Incident.

[2] He firmly believed that the international standard gauge was indispensable for radical improvement of Japanese railways—a view taken by Shinpei Gotō about 50 years earlier.

With the successful application for a $80 million loan (estimated to be no more than 15 percent of the cost of the line) in place, it ensured that the Japanese government had to remain committed to the project.

[1] In 1965, a year after the inaugural run, Sogo was decorated by Emperor Hirohito with the Grand Cordon of the Order of the Sacred Treasure, an award recognizing his extraordinary service to Japan.