In Joseon Dynasty, Busan Port was opened in 1407 and was an important city because it is close to Japan. The Korean government allowed Japanese to live in Busan because Busan was open to the trade between Korea and Japan since the 15th century and Japanese built houses and buildings. When the Imjin War occurred, Japanese people under the control of Toyotomi Hideyoshi invaded Korea in 1592, after Joseon Dynasty did not lead Japan to Min dynasty, Japan said that they needed the way to go to China and to conquer the Ming dynasty in China, but Japan changed its words and attacked Korea. At that time, Joseon Dynasty was not prepared for the war. Therefore, since Korea and the Ming dynasty had a good relationship with China, the Ming dynasty helped Joseon fight back Japan. When Toyotomi Hideyoshi died, Japanese solders went their county because they lost their hero and could not fight with both Korea and China.