In 2010, while he was filming "Three Sisters" in the mountain of Yunnan province, Wang Bing met two teenagers, Yonggao and Yongjin, whose father, a stonemason, had gone to the city in the hope of finding work. Wang Bing met up with them again in 2014, when they had been reunited with their father after four years in Fumin. For about a month, Wang Bing filmed their daily lives in the single squalid room that was their home. The fixed camera recorded the micro-events that punctuated their days : their father leaving for work, the youngsters themselves waking up, breakfast time, in front of the television, etc.