In the magazine Photoplay of November, 1929 Mr. Tsukamoto appears as a winner of a Honorable Mention for his film The Inland Sea of Japan but his name is spelled as Koji: "Aside from the honorable mentions already noted, another was given to Koji Tsukamoto,of Tokio, Japan, for his lovely 9 millimeter entry, "The Inland Sea of Japan." This contestant achieved some astonishing results with a difficult medium". Photoplay, Nov. 1929, 86. Koji is also stated as being from Tokyo, Japan in the 1937 December issue of Movie Makers.
Movie Makers, Dec. 1937, 602.