Su Jin, the struggling shopkeeper of the Su family, once saved Xiao Jue, the heir of the Marquis of Zhenbei, when he was in dire straits three years ago, giving him half a steamed bun. Three years later, Xiao Jue returns to repay his debt of gratitude. Burdened with debts, Su Jin is meticulous with every penny. With Xiao Jue's help, she applies modern business strategies to the ancient world, mastering business tactics such as hunger marketing and blind-box collaborations. She repeatedly humiliates Liu Ruyan, the rival who tries to suppress her. As they spend time together, the cold and aloof young marquis's heir completely falls for her, willingly becoming her loyal, hard-working assistant. Together, they conquer the business world, break monopolies, and build a top-tier commercial empire, while finding their way to a sweet love that is wholeheartedly reciprocated.