For years, the Levamme Empire has clashed with the Amatsukami Imperium in the shadows of war. Their battles have scarred the lands and split families. Amid this conflict, its prince professes affection for Juana del Moral and promises to conclude hostilities within twelve months as part of his nuptial pledge. Upon learning this, the Amatsukami launch an assault on the del Moral estate, aiming to eliminate Juana. The raid was swift, leaving devastation. To secure the bride for the prince, San Maltilia"s Airforce contracts a mixed‑blood mercenary—a bestado—named Charles, to covertly transport her to the Levamme capital. He agrees to the perilous task, yet navigating a lone ocean voyage into hostile territory turns out far more hazardous than anyone imagined.