Twenty - Fifth Army ( Japan ) The was an army of the Imperial Japanese Army during World War II , noted for its role in the Battle of Malaya and Battle of Singapore . History . The Japanese 25th Army was formed on 5 July 1941 under the Imperial General Headquarters . It was transferred to the control of the Japanese Seventh Area Army under the Southern Expeditionary Army Group on 6 November 1941 . Battle of Malaya . The Battle of Malaya began when the 25th Army launched an amphibious assault on the northern coast of British Malaya on 8 December 1941 . Japanese troops landed at Kota Bharu and advanced down the eastern coastline of the Malay Peninsula . This was made in conjunction with landings at Pattani and Songkhla in Thailand , where units then proceeded south overland across the Thailand - Malayan border to attack the western portion of Malaya . The Japanese were initially resisted by III Corps of the British Indian Army and several British Army battalions . The Japanese quickly isolated individual Indian units defending the coastline , before concentrating their forces to surround the defenders and force their surrender . The Japanese forces held a slight advantage in numbers on the ground in northern Malaya , and were significantly superior in close air support , armour , co - ordination , tactics and experience , with the Japanese units having fought in China . The Japanese also used bicycle infantry and light tank s , which allowed swift movement of their forces overland through the terrain that was covered with thick tropical rainforest . After defeating British and Indian troops at Jitra Japanese forces supported by tanks moving south from Thailand on 11 December , overwhelming British defenses . Penang was bombed daily by the Japanese from 8 December , and abandoned on 17 December . Arms , boats , supplies and a working radio station were left in haste to the Japanese . The evacuation of Europeans from Penang , with local inhabitants being left to the mercy of the Japanese , caused much embarrassment for the British and alienated them from the local population . Kuala Lumpur fell unopposed on 11 January 1942 . The 11th Indian Division managed to delay the Japanese advance at the Battle of Kampar for a few days , which was followed by the disastrous Slim River battle , in which two Indian brigades were practically annihilated . By mid - January the Japanese had reached Johore where , on 14 January , they encountered troops from the Australian 8th Division , commanded by Major - General Gordon Bennett , for the first time in the campaign . During engagements with the Australians , the Japanese experienced their first major tactical setback , due to the stubborn resistance put up by the Australians at Gemas . The battle , centered on the Gemensah Bridge , proved costly for the Japanese , who suffered up to 600 casualties but the bridge itself , which had been demolished during the fighting , was repaired within six hours . As the Japanese attempted to outflank the Australians to the west of Gemas , one of the bloodiest battles of the campaign began on January 15 on the peninsula ' s West coast near the Muar River . Bennett allocated the weak 45th Indian Brigade ( a new and half trained formation ) to defend the river ' s South bank but the unit was outflanked by Japanese units landing from the sea and the Brigade was effectively destroyed with its commander , Brigadier H . C . Duncan , and all three of his battalion commanders killed . On 20 January , further Japanese landings took place at Endau , in spite of an air attack by Vildebeest bombers . The final Commonwealth defensive line in Johore of Batu Pahat – Kluang – Mersing was now being attacked along its full length . On 27 January 1942 Percival received permission from the commander of the American - British - Dutch - Australian Command , General Archibald Wavell , to order a retreat across the Johore Strait to the island of Singapore . Following the successful capture of Malaya and Singapore , the IJA 25th Army served primarily as a garrison force for the occupied territories . As the situation grew increasingly desperate of Japanese forces towards the middle of 1945 , the IJA 25th Army came under the operational control of the Japanese Seventh Area Army , and its headquarters was transferred to Bukittinggi in the highlands of central Sumatra , which it held until the surrender of Japan in August 1945 .