A group of Lisu people without a registered ID (Hukou) live their primitive life in the mountains by the Nujiang River in Yunnan. In addition to misfortune and hardships, they also have simple happiness.
Rubel wants to join school but reality forces him to smuggle across the River Ganges between India and Bangladesh. The same river eroded his home. Now he lives on Char, an island within this river which starts eroding now.
This documentary is about a school in the mountainous area of Hunan and focuses on left-behind children in three families. Due to contradiction between backward rural appearance and urban development, the fate of the three generations interwoven together.