Leafie, a hen confined to a cramped battery cage and forced to spend her life laying eggs, dreams of one day escaping into the yard and living freely. When she finally breaks out of the henhouse, she reaches the yard she has long imagined, only to be treated as an outsider and driven away by the other animals. Venturing into the wider world, Leafie meets a talkative otter named Mayor and a mallard guard named Wanderer. She later discovers an abandoned duck egg and devotedly incubates it. When the egg hatches, Leafie accepts the young mallard, Greenie, as her son. Pursued by a one-eyed weasel intent on taking their lives, Leafie and Greenie eventually make their way toward the wetlands.

Based on Hwang Sun-mi’s novel of the same name, 〈Leafie, a Hen Into the Wild〉 features the voices of Moon So-ri as Leafie, Yoo Seung-ho as Greenie, Choi Min-sik as Wanderer, and Park Chul-min as Mayor. While the film gives its animal characters human speech and behavior, it also carefully incorporates the distinct ecologies and habits of chickens, ducks, otters, and weasels into the story. Rather than reducing the relationship between predator and prey to a simple conflict between good and evil, the film places all living beings within the cycle of nature, where one life is connected to another through both survival and death. Through a world in which different creatures live according to their own ways, 〈Leafie, a Hen Into the Wild〉 suggests that beings of different species, appearances, and ways of life can still come to understand, accept, and form relationships with one another.