Modern auditor Ye Cishu time-travels to ancient times, becoming the illegitimate daughter of the Ye family in Suzhou, transformed into an iron-rooster accountant. Relying on her precise auditing skills to tear apart scumbag men and steadily control the Baizhi Workshop. The hidden noble imperial prince Huangfu Shaoyu approaches under an alias to investigate a corruption case, signing a fake marriage contract with a life-saving medicine. The two go from meticulous calculation and mutual bickering and cooperation, to joining hands to ferret out the mole and solve major palace cases, turning the fake play into genuine love and gradually developing true feelings. Ye Cishu earns the imperial-bestowed plaque of "Dayu Calculation Master" by her ability, harvesting both career and romance, staging a clear-headed money-making yet sweetly doting ancient costume grand heroine thrilling drama.