@Grimmycoffee In the Chinese suzerainty system, the Emperor (皇帝) is the divinely ordained ruler of the world and the kings (王) are tributary rulers subordinate to the Emperor. The rulers of large states like Korea and Vietnam were customarily bestowed the title of kings by the Chinese Emperor to convey Chinese superiority in principle but in practice to grant them access to the Chinese cultural sphere. For a small tribute to be provided to the Chinese court each year, the subordinate kingdoms could gain access to Chinese trade, technology, manufactured goods, and military support. It was also oftentimes very useful for the ruling families of neighboring states to obtain the status of a tributary king because it implied to their subjects (especially their aristocracy) that removing them may invite an immediate military reaction from their giant neighbor. It was also therefore important for successful usurpers to petition the Chinese Emperor for recognition of kingship, because if they failed to do so they might create casus belli for the Chinese, their neighbors, their own subjects, or a combination of the former, to invade and replace them. Basically, under the suzerainty system legitimacy came from the Chinese court. It is, however, technically possible to demand recognition from the Chinese court of imperial status. In this case, the title would not be conferred like that of a tributary king but recognized by a diplomatic delegation, like those sent by the Song to the Liao court during the 12th century and those sent by the Ming to the Later Jin (Manchu) court in the 17th. This is what Hideyoshi tried to do in the story.