Fisherman Shen Haizhou is plotted against and thrown into a storm by his fiancée, solely to seize his savings and fishing boat. Hanging by a thread, he saves Ao Xi, the Dragon Girl of the East Sea, and is gifted the Pearl of the Vast Sea, enabling him from then on to breathe underwater, perceive fish schools, and control water to transform into a dragon. Rare seafood, centuries-old ambergris, and shipwreck treasures successively appear in the world. Leading his partners, he ventures into the deep sea, protects the East Sea, and runs a seafood business, slapping villains in the face all the way, while also going from repaying a debt of gratitude to staying together with Ao Xi, becoming the legendary Fishing King of the East Sea.