when Iwo-jima was chosen to attack but were subjected to bombing and naval shelling by the U.S. military. 2nd Brigade The 2nd Independent Mixed Brigade, led by Major General Kotau Osuga, and the Third Battalion of the 17th Regiment, led by Major Tomachi Fujiwara, was on Iwo Jima with Kuribayashi. The 2700 man 145th infantry regiment under Colonel Masuo Ikeda, a part of 46th division, was diverted from Saipan to Iwo Jima and Rear Admiral Toshinosuke Ichimaru that arrived with 2300 navy personnel. Many of the 109th's personnel had previously served in China, Burma and the Dutch East Indies and had become reservists who were now reluctant to go back to battle. To bolster morale the Japanese Emperor Hirohito sent his own palace guard of anti-aircraft gunners to Chichi Jima to support the troops—as it was expected the main force of Americans would strike there, however the Allied Joint Chiefs of Staff decided to bypass Chichi Jima altogether. Preparations With preparations underway Kuribayashi worked with the tactic of defense-in-depth building numerous pillboxes for machine-gunners and 13,000 yards of tunnels with even a field-hospital worked in. However he had issues with many officers—dismissing 18 of them along with his Chief-of-staff, Kuribayashi also lost control of the Naval troops who dug in on the beaches. The Battle Begins On 19 February 1945 the battle began, but quickly came the feeling that the 109th were doomed as air or naval relief would not be able to help. Kuribayashi ordered his troops to inflict maximum damage and casualties on the enemy and to "kill 10 men before dying". For 33 days the 109th fought on Iwo Jima, facing against tanks and heavy bombardments from the sea and air. In the end only 1083 Japanese survived, with a mere 216 captured from the 109th's 21,000 men during the battle, the other 867 Japanese soldiers came from other units. As for Kuribayashi, it is generally thought that he committed suicide by leading the last major counterattack. The rest held out hungry and alone in Iwo Jima's tunnels until the U.S. soldiers used explosives to clear the tunnels weeks later. Elements of the 109th The 109th Division comprised the 1st and 2nd Mixed Brigade. The 3rd Battalion of the 17th Independent Mixed Regiment was on Iwo Jima and there were many attached units Headquarters Group The 109th Chief of staff (detached to Chichi jima); Colonel Hori, was