The 46th division was initially assigned to the Western District Army to strengthen the mainland defenses.

[2] The Division's 123rd Regiment landed in Sumba of the Lesser Sunda Islands in late November 1943.

The remaining 145th Regiment was unable to be transported and instead was diverted from Saipan in June 1944 to Iwo Jima under the Lieutenant General Tadamichi Kuribayashi's Ogasawara Corps, where it was wiped out in the Battle of Iwo Jima in February - March 1945.

Consequently, the 123rd and 147th infantry regiments were removed from Sumba and Sumbawa islands, respectively, and sent to Malay Peninsula in April 1945, landing in Singapore.

These were disbanded at Kluang, Johor province after the surrender of Japan 15 August 1945 (79 years ago) (1945-08-15).