"Japs" on hand-painted Mt. Fuji card. The message on this card reads: "Fujiyama, the mt. (mountain) the Japs worship. Been seeing Yokohama in a jinrichisha (rickshaw). Feb. 14."
This person apparently learned a few Japanese words like "jinrikisha" which means "human-powered vehicle" that is the rickshaw. And the term "Japs" has been around well before World War II.