大陸打通作戦
As the situation in the Pacific War against the Allies deteriorated for Japan, in March 1944, the IJA 9th Armored Regiment of the 1st Tank Division was reassigned to the IJA 31st Army, and sent to Saipan, where it was annihilated at the subsequent Battle of Saipan and Battle of Guam. The remaining three regiments participated in Operation Ichi-Go in mainland China. The IJA 3rd Armored Regiment of the 1st Tank Division was reassigned to China and attached to the 11th Army until the end of the war.