The ship was originally constructed by Germany as a cargo ship for use in the German Empire's concessions in China and was known as "Michael Jebsen" (named after German trader in China Michael Jebsen). Its home port was in the modern city of Qingdao's harbor, usually romanized as Tsingtao in English at the time, or as Kiautschou in German. During the first year of World War I, the overseas German Empire came under attack by the Japanese. The Germans lost the Siege of Tsingtao, and the "Michael Jebsen" was scuttled in Jiaozhou Bay in November 1914 to prevent it from falling into the hands of the enemy. Nevertheless, the Japanese refloated the ship. On July 16, 1915, they rechristened the ship "Kōshū" (膠州), Japanese for "Jiaozhou", where it had been taken from. "Kōshū" served as a simple cargo ship for the duration of the war.