"Flyweight" is the minimum weight for boxing matches.

Until she was 11, Colette lived in the shadow of her twin sister Lison, the more beautiful and gifted one. Then Lison died in a car accident. Their mother was driving and lost an arm – and her favorite child. Colette stubbornly pursues ballet, in which Lison excelled, drawing sharp comments from her shadow... because since her sister's death, her shadow has been talking to her, and doesn’t mince words. While Colette is timid and wary, her shadow pushes her to take risks and fulfill her dreams.