Yin and Ning are two sisters who have been wandering the land together ever since their village was destroyed by the villainous Taibai Empire. Their childhood friend, Zhao, has been enslaved by the Taibai himself, and uses his brilliance at tinkering and inventing to get by as a slave to the Empire's whims. One day, Yin accidentally discovers a legendary sword, which grants her fantastic abilities in combat, and allo...