Young princess Finé, the daughter of the Archduke of a small alpine country, travels to the neutral land of Westria to seek help against the Germanian empire that is invading her kingdom. But her plans go awry when she's captured by the Germanians, and transported by air back to their capital of Neu-Berlin. Then a strange light appears at the back of the plane, and a witch begins to awaken...

Finé and Izetta escape the burning wreckage of the plane on the back of a rifle. But squad of Germanian pilots participating in the invasion of Eylstadt hear the transport's distress call and move to intercept them. Izetta is forced to use her magic to fight them off, breaking the rule her grandmother gave her. When the enemy planes are shot down and driven away, Izetta takes Finé to join the retreating Eylstadt army, where she reminisces about how they met.

Izetta's victory has won a brief peace for the dukedom, and the princess intends to enjoy it. Together, they practice dancing, and go to a pie shop. But there's trouble brewing in the background, as young private Jonas has discovered her secret. How far is Seig willing to go to keep the country safe, especially when innocents are involved?