In the early Republic of China era, Liuhe Village in Jiangnan. To the east of the village lies a mysterious river called Hexian Ferry. Every full moon, a woman in white emerges from the river, calling herself Hexian. The custom of valuing sons over daughters is prevalent in the village, so Hexian sets a rule: whenever a family has an unwanted baby girl, young girl, or maiden, as long as they attach the biological parents' names and birth characters, and place them in a small boat pushed into the river, they can exchange her back for an equally aged, healthy, and smart boy. Zhang San of the village uses his newborn baby girl to exchange for a big chubby boy, Li Si uses his four-year-old daughter to exchange for an eloquent literary star, and Wang Wu intends to use his ten-year-old daughter to exchange for the talent of a top scholar, but is exposed on the spot by Hexian because his daughter is not biologically his.