Is Chu king or something?

Zhou Wuwang honored the royal family as a vassal state. At that time, Song was the highest-ranking principality because it was descended from the Shang Dynasty. His Qi State, the leader of Jiang Ziya's heroes, and Ji Fa's brothers, such as Lu State and Yan State, all belonged to the vassal state. The so-called thousands of vassals were these vassal States and sub-States. Chu is the sub-country with the lowest rank, so when Chu became strong, he asked to raise their rank, but it was rejected. He angrily claimed to be king, but it was not recognized by other countries.