Su Yu, the eldest daughter of the richest family in Haicheng, transmigrates into the body of a favored concubine of the tyrant of the Great Zhou Kingdom. To stay alive, she waits for the rare celestial alignment of nine stars to return home. When an assassin attacks, she uses the tyrant, Xiao Heng, to shield herself from a sword, provoking his fury and an order to execute her. Just then, the nine-star alignment appears, and Su Yu returns to the modern world. However, she soon discovers that the tyrant has followed her. Initially terrified, she begs for mercy before quickly realizing that she is on her own turf and has no reason to fear him. Meanwhile, Xiao Heng is astonished by modern life and its many unfamiliar wonders. After a series of twists and turns, Su Yu and Xiao Heng gain a new understanding of each other and eventually become a couple.