31st Division ( Imperial Japanese Army ) The was an infantry division in the Imperial Japanese Army . Its call sign was the . History . The 31st Division was raised in Bangkok , Thailand , on March 22 , 1943 out of reservists from Fukuoka prefecture . It was assigned to the Japanese 15th Army . In 1944 , under Japanese operation U - GO , Lieutenant General Renya Mutaguchi ordered the 31st Division across the border of Burma into British India as part of the overall Battle of Imphal . Its assignment was to capture Kohima , thus cutting off Imphal , and then exploit to Dimapur . The 31st division ' s commander , Lieutenant General Kotoku Sato was unhappy with his role . He had not been involved in the planning of the offensive , and had grave misgivings about their chances . Sato and Mutaguchi had also been on opposite sides during the split between the " Toseiha " and " Kodoha " factions within the Imperial Japanese Army during the early 1930s , and Sato distrusted Mutaguchi ' s motives . In addition , along with many of the senior Japanese officers in Burma , he considered Mutaguchi a " blockhead " . Starting on March 15 , 1944 , the 31st Division crossed the Chindwin River near Homalin and moved northwest along jungle trails on a front almost 100 kilometers wide . The left wing of the division , the 58th Regiment , commanded by Major General Shigesaburo Miyazaki clashed with Indian troops of the Indian 50th Parachute Brigade under Brigadier Hope - Thompson at Sangshak , on the northern approaches to Imphal on March 20 . The battle continued for six days , and Miyazaki was handicapped by lack of artillery . Eventually , as the IJA 15th Division ' s troops joined the battle , Hope - Thompson withdrew . The battle cost Miyazaki about 400 men and delayed his attack on Kohima by a week . Miyazaki ' s troops were probing Kohima on April 3 , completing siege preparations by April 6 . He then launched a series of attacks into the north - east region of the defenses on April 8 , and by April 9 the British and Indians had been forced back driven into a small perimeter into what came to be known as the Battle of the Tennis Court . By the night of April 17 , the defenders ' situation was desperate . However , on the morning of April 18 British artillery opened up against the Japanese positions , which stopped the attacks . To support their counterattack , the British had amassed 38 3 . 7 - inch mountain howitzers , 48 25 - pounder field guns and 2 5 . 5 - inch medium guns . The RAF also bombed and strafed the Japanese positions . The Japanese could oppose with only 17 light mountain guns , with very little ammunition . The road between Dimapur and Kohima had been opened , and the siege was lifted . The Japanese did not retreat at once , but stayed in position and fought tenaciously for several more weeks . By the morning of May 13 , most of the Kohima region had been re - taken by the British forces . Around May 15 the 31st Division began to withdraw , pursued by troops of the British Fourteenth Army . After ignoring orders for several weeks , Sato was removed from command of the 31st Division early in July . The entire Imphal offensive was broken off at the same time . Lieutenant General Slim had always derided Sato as the most unenterprising of his opponents , but Japanese sources blame his superior , Mutaguchi , for both the weaknesses of the original plan , and the antipathy between himself and Sato which led to Sato concentrating on saving his men rather than driving on distant and indefensible objectives . The surviving remnants of the 31st Division continued to oppose the British reoccupation of Burma , but for all practical purposes , the 31st Division had largely ceased to exist after the Battle of Kohima . Organization . The order of battle for the 31st Division included : IJA 31st Division