Every spring, China's 130 million migrant workers travel back to their home villages for the Chinese New Year's holidays. This exodus called Chunyun is the world's largest human migration. Working over several years, director Lixin Fan traveled with one couple who has embarked on these annual treks for almost two decades. Like many of China's rural poor, the Zhangs left their native village of Huilong, Daan Town [zh], Guang'an District in Sichuan province and their newborn daughter to find work in Guangzhou in a garment factory for 16 years and see her only once a year during the Spring Festival. Their daughter Qin, now a restless and rebellious teenager, resents her parents' absence and longs for her own freedom away from school and her rural hometown, much to the dismay of her parents. She eventually leaves school, against the wishes of her parents, to work in the city.