It was first conceived by author Shunrō Oshikawa in his 1899 novel Kaitei Gunkan ("Undersea Battleship"), of which Atragon was an adaptation produced by Toho Studios.
Oshikawa entered the publishing company Hakubunkan at the introduction of the author Iwaya Sazanami (1870–1933) and served as a lead reporter for "Shaijitsu Gahō" (写実画報 lit. Graphic Pictorial), a magazine that featured stories and photos about the Russo-Japanese War of 1904.