Koutei Heika no Chouki ni Goshimei saremashita

I, a commoner, was suddenly appointed as His Majesty's concubine!? It seems that the Emperor has a reason for this.. A Chinese-style Cinderella story!! Dancer Hualien decides to participate in the banquet where the emperor is searching for a concubine in order to save his sick sister. However, he unexpectedly learns the secret of Emperor Liuyue..?