Traveling entertainers Yin and Ning are very close sisters. Yin cares for her armless sister as they travel between villages, putting on performances of swordplay and dancing. When they arrive in the ruins of a village, they find a mysterious bamboo writing strip. The strip glows, and from within it a strange girl and a single sword appear. Meanwhile, in the Taibai Empire bent on conquering the Shenzhou region, a boy name Zhao is working as a slave. Zhou, who has been teaching himself engineering, meets a young girl one night.