Who is Robbers in Puyo from A Single Shard and what is their importance?

The robbers in Puyo attack Tree-ear at the Rock of the Falling Flowers, where they overpoer him and try to steal his jiggeh. They take Tree-ear's money and toss the two pots he is carrying to Songdo off the cliff. The pots shatter on the rocks below, leaving Tree-ear with a single shard.