The Candy Thief - Gilbert Bordes - book

Matthew is twelve years old and doesn't do anything at school. Occasionally, he steals. "We'll never do anything with him," his grandmother laments. The whole village agrees.
Manon arrives. They're the same age. He's radiantly healthy; she's gravely ill. To bring a smile to her pale lips, he needed gifts: candy, a necklace, a lighter—all stolen, of course. And because Marion tells him she feels better after taking communion, one day he goes too far. The ciborium and the hosts disappear. Scandal in the Corrèze hamlet!
Five years in a reformatory, and Matthieu is free. He hasn't stopped thinking about Marion...