Once Toyotomi Hideyoshi made the decision to invade Korea, he took the most strategic path. Japan attempted to invade Korea starting from its own Northwest and progressing into Korea's Southeast corner. The attacks in 1592 and 1597 were focused on the South Eastern corner of the peninsula. Japanese forces focused on the town of Busan in their initial movements onto Korean land. Hideyoshi reasoned that the use of Japanese weapons such as muskets would overpower the town. He was right. Busan fell to the Japanese forces in quick time.
In concentrating on overtaking Korea from the South, it was thought that inroads could be made throughout the region. Japanese commanders were able to use Busan as a staging area, from which other advances could be made. In Japan's attempt to invade Korea, the pattern of tactical movement swept across the peninsula in a Northwest manner. The theory at the time was that continued Japanese successes could be used to capture Seoul and then from Seoul, a movement into China was not out of the realm of possibility. Coveting further territory in the region became the emphasis with a progression into Pyongyang. This became the focus as Hideyoshi believed that Japanese forces would make quick work of the opposition.
The challenge for the Japanese was evident as they further progressed throughout the peninsula. Moving from Southeast to Northwest strained the Japanese ability to move resources and supplies to the men fighting. Adding to this was resistance from the Koreans. The Koreans chose to fight and resist, as opposed to simply capitulate. Hideyoshi underestimated the use of guerrilla tactics and their withering effect on the Japanese forces, who were already stretched beyond capacity. The disruption of supply lines to troops took a toll on the Japanese. The invasion of Korea from its Southeast corner worked initially. As the invasion cut across Korea into its Northwest parts, the challenge of reinforcing troops began to weigh on the Japanese, helping to force the stalemate once Korean resistance and Chinese fortification emerged.
Japan under the leadership of Toyotomi Hideyoshi attacked Korea in 17 century to take over ChoSeon(Ancient Korea). At first, Hideyoshi only sought to conquer Ming China and requested passage through Korea to do so. However, Korea refused since they were close allies with Ming China. This led to the Japanese Invasions of Korea, in which Korea, allied with Ming China, defeated the Japanese invading forces twice. The reason why Japan attacked (in the 19th to 20th century) was because Japan wanted man power and the food capablity Korea had.