Yu traveled around the world and transformed it into Kyushu. In ancient times, there were many animals and few people, so the people lived in their nests to avoid them. Later, when he traveled around, the Taoist discovered the secret method of commanding animals with runes, which he called a contract. After his ascension, to prevent cunning people from stealing it, he divided his secret knowledge into thirteen volumes and distributed them in Kyushu. Later generations called this the Thirteen Strategies of Kyushu.