Officially, The purpose of the Turtle (or Tortoise) Clan is to serve as diplomats and couriers for the Imperial families, but they are not an Imperial family in itself. Their duties often lead them to labors many think not honorable, like commerce, heavy labor and interaction with gaijins. The interesting part is that this is only a façade, because they always secretly have been spies, smugglers and enforcers for the Emperor. While formerly the Hantei Emperors have technically been the daimyo of the Tortoise, Toturi bestowed the leadership upon the clan members themselves. Actually they're serving faithfully Hantei Naseru.