Siege of Jinju ( 1592 ) The Siege of Jinju was one of two battles during the Japanese invasions of Korea ; the first in 1592 , and the second in 1593 . The second battle of Jinju was not as successful , and it fell to the Japanese . Prelude . Jinju castle was an important castle that guarded Jeolla province . Ukita Hideie and Hosokawa Tadaoki agreed on taking Jinju castle because if the Japanese captured it , it would open up a new road to Jeolla , and they would be able to attack Gwak Jaeu ' s guerilla forces hiding in the area . Jeolla was also place for plenty of loot . Ukita also agreed to recapture Changwon , a small fortress that led to Jinju castle . Therefore , an army of 30 , 000 men to recapture Changwon and Jinju set out . Yu Sung - in , Commander of right Gyeongsang province , placed his army to in front of the gate of Jinju . General Yu Sung - in requested a permission to enter into the Jinju . However , Japanese arquebuses reached behind the reinforcements . Kim Si - min inevitably reject a request , and Yu Sung - in ultimately agreed to the Kim Si - min ' s words . The reinforcements were annihilated by the Japanese Arquebus es . Siege of Jinju . The Japan ese heartily approached Jinju fortress . They expected another easy victory at Jinju but the Korean general Kim Si - min defied the Japanese and stood firm with his 3 , 800 men . Again , the Koreans were outnumbered . Kim Si - min had recently acquired around 170 arquebuse s , equivalent to what the Japanese used . Kim Si - min had them trained and believed he could defend Jinju . The Japanese charged and began to bring ladders to scale the wall . They also brought a siege tower to try to gain the higher ground . As a counter , the Koreans unleashed massive volleys of cannons , arrows , and bullets . Surprised , Hosokawa tried another angle of approach by using his arquebuses to cover the soldiers scaling the wall . This still had no success because the Koreans ignored the bullets and smashed ladders with rocks and axes . When the Koreans began to lob mortars down at the Japanese , the Japanese began to lose even more men . After three days of fighting , Kim Si - min was hit by a bullet on the side of his head and fell , unable to command his forces . The Japanese commanders then pressed even harder on the Koreans to dishearten them . But the Koreans fought on . The Japanese soldiers were still unable to scale the walls even with heavy fire from arquebuses . The Koreans were not in a good position since Kim Si - min was wounded and the garrison was now running low on ammunition . Reinforcements . Gwak Jae - u , one of the main leaders of the Righteous armies of Korea arrived at night with an extremely small band , not enough to relieve the Koreans at Jinju . Gwak ordered his men to grab attention by blowing on horns and making noises . About 3 , 000 guerrillas and irregular forces arrived at the scene . At this time , the Japanese commanders realized their danger and were forced to abandon the siege and retreated . Aftermath . The Righteous army was too small to relieve Jinju . But , the retreat of Japanese soldiers heartened the Koreans and the biggest thing earned from the siege was that the Korean morale was boosted greatly . The first battle of Jinju along with the Battle of Hansan Island and the Battle of Haengju are regarded as the three most important battles of the war .