The Japanese printed these notes for several areas in anticipation of their takeover in WW2.
These are Malayan as shown and through the prefix M. There are also notes for the Philippines, in Pesos and cents, Indonesia in Roepiah and Sen (In Dutch), Australia and Pacific in Shillings and Pounds as well.
Generic designs were used for all denominations from One cent/sen/ etc up to 1000 of Dollars, Pesos, Rupiah and only to Ten Pounds.
Most are common, yet interesting. Malayan and Philippine notes got some use along with Indonesia, but Pacific/Australian ones never did.
I love coins. Especially silver, gold and anything really old.
Member of the Royal Numismatic Society of New Zealand and the Auckland Numismatic Society