In this case, the red circular cancellation postmark is dated 18.12.8. In the Japanese imperial calendar (Showa era), "18" refers to Showa 18, which is 1943. The full date, 8 December 1943, is significant as it was the second anniversary of the attack on Pearl Harbor (which occurred on 8 Dec., Japanese date).
Postcards like this one were produced by organisations like the Army Art Association to boost domestic morale and spread propaganda, often depicting soldiers in idealized, peaceful, or heroic settings. They were common during the Second Sino-Japanese War and World War II. These "Gunji Yubin" (Military Mail) cards allowed soldiers to communicate with their families while serving in occupied territories like China or Southeast Asia.
The illustration depicted a Japanese soldier standing in a flowering wisteria tree, serving as a "lookout" or "observation post (tenbōshō). This specific artwork is signed by the artist Mori Shunchō (森春鳥).
The characters (中豐) inside the postmark likely referred to a specific field post office or military location where the card was processed, possibly in occupied territory like Central China.
The purple stamp (left) is a 1/2 sen definitive postage stamp from Japan's First Showa series, issued between 1937 and 1940. The stamp featured a traditional Japanese cargo ship, known as a sengoku-bune.
The blue 1½ sen stamp (right) is from the Tazawa series (named after designer Tazawa Shogen). It was issued during the Taisho era, specifically starting around 1913 till 1931.
Both stamps contain the Imperial Chrysanthemum Crest at the top centre, flanked by decorative vine patterns.
