Su Yan, a modern financial expert, transmigrates to the Great Qian dynasty and finds himself in the body of a notorious, spoiled young nobleman from a ducal family, despised by everyone. His predecessor was seriously injured after being plotted against by the Xue family and was also ordered by imperial decree to marry Princess Anning. Su Yan is determined to break off the engagement. Relying on modern knowledge, he invents hand-cranked fans, milk tea, and refined white sugar. He uses saltpeter to make ice, shattering the Xue family's monopoly on ice. He then partners with the princess, who conceals her identity, to go into business, making a fortune together. When court officials turn against the Su family, Su Yan dares to slap Duke Xue and voluntarily takes responsibility for disaster relief, implementing a work-for-relief program to provide for displaced refugees. Once dismissed as a wastrel, he uses extraordinary business acumen and remarkable courage to navigate the royal court and powerful noble families while looking after the common people, overturning everyone's prejudices.