The movie spends about ten minutes introducing the background:
By the year 2700, Blue Star was left only with garbage and robots.
This robot, known as Wally, was produced by a robot company and is a low-grade robot tasked with cleaning up the garbage on Blue Star.
At this time.
With Blue Star's environment deteriorating, humans had already entered outer space, leaving countless free-operating Wally robots to clean up Blue Star.
Centuries.
All the Wally robots had exceeded their service life, breaking down one after the other, except for this Wally, which strongly survived and even gradually developed human emotions.
Wally didn't forget its duty.
Every day, it cleaned up garbage that it was destined never to completely clear away.
However.
At the end of each day's work, Wally would feel lonely.
The only living creature it could interact with was a small cockroach that always followed it.
