Chen Wanghai, a live-in son-in-law, has endured endless mistreatment in the Lin family. To obtain the bride price, his father-in-law, Lin Dashan, and mother-in-law, Liu Guixiang, plan to marry their daughter, Lin Niannian, off to Zhou Qiang. To save his daughter, Chen Wanghai risks his life by going out to sea during a deadly black tide. At the brink of disaster, he is rescued by Xiao Cai, a spirit fish he saved three years ago. Guided by Xiao Cai, Chen Wanghai catches huge quantities of wild large yellow croaker, earning enough money to pay the bride price and cancel the marriage. However, this earns him Zhou Qiang's hatred. The two make a fishing wager at sea, and Zhou Qiang secretly poisons Chen Wanghai and sabotages his fishing boat, but Xiao Cai detects every scheme, allowing Chen Wanghai to win time and time again through his own experience.