The battle between the Levamme Empire and the Amatsukami Imperium has been raging for years. Within the midst of this wrestle, the prince of the Levamme Empire declares his love for Juana del Ethical and vows to finish the battle in a single 12 months, as a part of his marriage proposal. When the Amatsukami catch wind of this, they assault the del Ethical residence, focusing on Juana's life. As a last-ditch effort to convey the prince his bride, the San Maltilia Airforce employs a mercenary of combined blood—a bestado—to fly Juana to the prince in secret.