The final military currency issued before the Shōwa era is referred to as . Towards the end of World War I Japan sent troops to support the allied intervention in Siberia against Soviet Russia and its allies during the Russian Civil War. Gold backed banknotes issued by the Russian government were widely accepted in Siberia and Manchuria before the start of World War I. When the October Revolution caused the Russian monetary system to become chaotic the Japanese looked for ways to exploit the situation by releasing their own currency in the regions. The Japanese government decided in July 1918 that military payments should be made through the Bank of Chosen using banknotes or gold backed military notes These notes were backed by 10,000 yen in gold coins as military funds given for the duration of the event. Siberian Intervention Warbonds were issued in August 1918 when the event commenced in denominations of 10 sen, 20 sen, 50 sen, 1 yen, 5 yen, and 10 yen. Their size ranges from 109mm x 76mm for sen to 135 mm x 95 mm for yen with a design similar to Meiji Tsūhō notes that were issued for civilians in Japan from 1872 to 1899. The face value of these notes is written twice in both Japanese and Russian on the obverse side to reflect issuance in the regions involved. These notes circulated for a long duration as the Imperial Japanese Army continued to occupy Siberia even after other Allied forces withdrew in 1920. Siberian Intervention Warbonds were actively collected by the Japanese government when soldiers returned from the intervention in October 1922. Those that weren't collected remained in circulation as convertible banknotes that could be exchanged for Bank of Japan notes of the same value. This period of exchange lasted until September 1945 when the Ministry of Finance declared the military bonds invalid.