In 1941, the division was assigned to the 15th Army and participated in the Japanese conquest of Burma.

During the Burma Campaign, the 144th Infantry Regiment was detached from the division and sent to New Guinea.

The rest of the 55th was used to counter an ill-planned[1] British attack at Donbaik (Sittwe (Akyab)) from 18 March 1943.

By 3 April 1943 the division had started to advance past the Mayu range, eventually surrounding and defeating a number of British units; encountering stiffer resistance from May 1943 onwards.

[2] Finally, the division fought a failed offensive which become the Battle of the Admin Box in February 1944.