Shasha, a robot living in 2121, has a dream to make the world free of sewage, sand and garbage. On this day, every piece of land on the earth turned into a desert, and all vegetation disappeared. In order to prevent starvation, scientists asked Shasha and some other small robots to ride a space-time machine back to 2021 to collect plant seeds. What they didn't expect was that just after arriving in 2021, someone among the robots destroyed the time-space machine...
Purpose: Protect our home planet and care for every inch of land