Tree-ear and Crane-man have spent the better part of ten years living under a bridge. They are both very poor and have nowhere else to live. Without money, the young orphan and his protector are forced to scavenge food wherever they can. (Even if it's from a garbage heap). But one thing they won't do is steal: for Crane-man, this would be a shameful thing to do, no matter how hungry they might get.
In the time and place where the story is set—twelfth-century Korea—it was all too common for orphans like Tree-ear to find themselves forced to live on the streets. There was no government provision for the poor, no welfare system that could act as a safety net to protect people from the worst effects of poverty. Even children didn't receive any help. For orphans like Tree-ear, life could be very bleak. If they weren't lucky enough to have a relative who would agree to take them in, they were pretty much on their own. Thankfully, Tree-ear has Crane-man to look after him, even though he's still homeless and has to live under a bridge.