Who is Bobby Ngu from Tropic of Orange: A Novel and what is their importance?

Bobby did not have much of a childhood. He was thrust into a role of responsibility at an early age. Bobby is Chinese and originally from Singapore. After his mother died, and after his father's business began to fail, Bobby's father suggested that Bobby and his younger brother take advantage of the growing amount of Vietnamese refugees being housed in camps in Singapore while waiting to be allowed into the United States. Bobby and his brother began going to the camp every day and passing themselves off as orphaned Vietnamese children. In time they received clearance to move to the United States.