Sheena is an orphan who is trained for war, even though she doesn't want to be. And one day, she meets Mimi.

Sheena, Mimi, and their classmates get sent into the forest to fight 100 magical enemies in a combat exercise.

After Sheena realizes she wants to make friends with Mimi, Mimi decides to share an important secret with her.

Sheena tries to learn more about Mimi's condition but is confronted by Ms. Fran and sworn to absolute secrecy.