On 15th February 1942, the whole of the Malaya Peninsula was occupied by the Japanese Government following the fall of Singapore. As a result of that, a Japanese Military Administration was set up and Malaya was renamed ‘Malai’.
During the occupation of Japanese Government, the Japanese introduced new currencies as a replacement of those previously in use in the occupied territories of Malaya, North Borneo, Brunei and Singapore. The new currency in Malaya and Singapore were issued at the par value with the existing British Malaya currency notes (Malayan dollar) and first entered circulation in 1942. The first series of Japanese occupation notes had serial numbers, but these were later omitted leaving the control letter "M", meaning Malaya.
The Japanese authorities simply printed more notes whenever they required it. This resulted in high inflation and a severe depreciation in value of these notes. Moreover, counterfeiting was rampant due to its lack of a serial number on their notes.
The Japanese occupation notes were also well known as Banana Notes. It was named as such because of the motifs of banana trees on 10 dollar banknotes.