Modern person Gu Hai crosses over to ancient times, becoming an abused live-in son-in-law in a seaside fishing village. Right at the start, he encounters the Su family's preference for boys over girls, wanting to sacrifice the newly born fourth daughter to the sea. Gu Hai angrily rescues the young daughter, takes his wife and daughter to separate the household and stand on their own. Relying on modern business wisdom, starting from selling seafood claypot porridge and making fish sauce, he step by step establishes a business empire. While fighting against malicious relatives and local powerful gentry, he rescues the imperial grandson stranded among the people, accidentally getting involved in court power struggles. In the end, Gu Hai relies on extraordinary strategy to defeat Prince Jing, counterattacking to become the magistrate of Linhai, and further helping his four daughters display their respective strengths, writing a legendary story of protecting his wife and doting on his daughters, doing business to get rich, and stepping step by step to the summit.