Covered in ice and snow, Elior Forest is the home to dangerous magical beasts and 50 elves frozen in ice. One day, the great spirit Puck helps a young girl break out of her ice prison. Her name is Emilia, a half-elf born with silver hair, long ears, and amethyst eyes—features that resemble the evil Witch who destroyed half the world long ago. Shunned by society because of her appearance, Emilia dwells in the forest with Puck as her sole companion and family. Burdened with a sin of destruction she does not remember committing, she spends her days trying to find a way to help her frozen kin. But when the great spirit Melakuera, the Arbitrator of the world, finds Emilia, her right to stay alive is brought into question. Will the bonds of ice she formed with Puck prove to be the warm thread that defies fate?

Subaru and friends finally get a moment of peace, and Subaru goes on a certain secret mission that he must not let anyone find out about! However, even though Subaru is wearing a disguise, Petra and other children of the village immediately figure out who he is. Now that his mission was exposed within five seconds of it starting, what will happen with Subaru's "date course" with Emilia?