Who is Francis from Swimming Lessons and what is their importance?

In "One Sunday," Francis is a short, powerful young man, apparently of limited intelligence, who does odd jobs for everyone in C Block to earn a living after being dismissed from the furniture store across the street, under whose awning he continues to sleep. To the Boyces' chagrin, Francis mentors Kersi in the art of flying a kite, and the two play tops and marbles together. Najamai returns home late from a visit to her sister to find Francis crouching in her kitchen, believes he has stolen money from her, and alerts the neighbors. The Boyce boys chase him into rough Tar Gully, where the street people beat and kick him as a thief, and he is hauled back to face Najamai's charges. Kersi in later years doubts Francis' guilt, but he has disappeared.