Down-and-out heir Gu Jingchuan, in order to save his ancestral Zuixian Restaurant, accidentally discovers a mysterious door in the back kitchen leading to a modern supermarket. Using modern business models, he introduces novel goods such as instant noodles, hot pot, and milk tea into ancient times. Through marketing methods such as limitations, membership systems, and combo packages, he brings the failing restaurant back to life. Facing creditor harassment, peer sabotage, and the schemes of a family that broke off an engagement, Gu Jingchuan plans every step carefully. Not only does he successfully slap all opponents in the face, but he also develops Zuixian Restaurant into a catering empire covering three provinces, ultimately winning the prestigious honor of "Imperial Kitchen Designated Supplier." Solely focused on making money and refusing arranged marriages, he uses an abacus to calculate all business under heaven, opening up his own commercial legend.