In World War I, Japan was against Germany.In 1898, Germany had signed a 99 year lease with China and built the port of Tsingtao on Kiaochow Bay. The Germans also built a brewery that provides Tsingtao beer to this day. In August 1914, Tsingtao was manned by a force of 3,000 German regular army and commerical interests that formed a "Home Guard." On 31 Oct 1914, a Japanese fleet including 6 battleships and 50,000 troops attacked Tsingtao. 200 Germans were killed and the remainder taken prisoner and sent to Osaka POW camp on the island of Japan. When the war ended 11/11/1918, Most of the Prisoners were suffering from the influenza epidemic. Many lingered into 1920, never getting well enough to be returned.
www.tsingtau.info/geschichte/gestorbene.htmlists 3000 German soldiers and Home Guards who died in Tsingtao or in a POW camp. 40% died from the "Spanischen Grippe".