Innocence (2004)

At an unusual private school for girls, new students, including young Iris (Zoé Auclair), show up in coffins. The establishment's teachers, Mademoiselle Eva (Marion Cotillard) and Mademoiselle Edith (Hélène de Fougerolles), introduce Iris and her fellow pupils to the school's curriculum, which includes fairy-like dances through a nearby forest. When night falls, the older girls, who are on the threshold of womanhood, are then given mysterious, life-changing lessons.