In 1592, Toyotomi Hideyoshi led a Japanese invasion of Korea which at the time was under the Joseon Dynasty at the time with later plans to begin a conquest of Ming Dynasty China. Although the Japanese did come to occupy the entirety of the Korean Penninsula, the combined armies of Ming and Joseon forces which were numerically superior proved too much for the Japanese forces and, in 1598 with a tactical stalemate, the Japanese withdrew for good.
But...what if the Japanese had won?
Lets assume for a moment that Hideyoshi's forces prevailed in the face of superior numbers. What would the implications be of a Japanese victory at the time and beyond?