Japan invaded the Philippines on 8 December, 1941 only hours after the attack on Pearl Harbor. Within days, Japan had bombed airfields and successfully disabled the U.S. Air Force in the region.

In 1942 Japan issued 1, 5, 10 and 50 centavos and 1, 5 and 10 Pesos. The following year, additional 1, 5 and 10 Pesos notes were printed with and illustration of the José Rizal monument in Rizal Park, Manila, Philippines. In 1944, with inflation spiralling out of control, 100 peso notes were introduced along with 500 peso notes soon after. In early 1945,  the Japanese issued 1,000 peso notes.

JIM for the Philippines was produced in the following denominations: One Centavo, Five Centavos, Ten Centavos, Fifty Centavos, One Peso, Five Pesos, Ten Pesos, One Hundred Pesos, Five Hundred Pesos and One Thousand Pesos.

Photo: Petty officer Hewitt from the Australian Navy with a captured truck full of Japanese invasion money near Manila in 1945.
Could these notes have gone on to be overprinted in Brisbane, Australia and air-dropped back over Manila?