Carlo Levamme, Crown Prince of the Levamme Empire, proposes marriage to noblewoman Juana del Moral (Fana del Moral) to solidify political alliances amid the Empire's war with the Amatsukami Imperium. This arranged union is delayed by prolonged conflict. Following the bombing of the del Moral residence and the death of Juana's father, Diego del Moral, Carlo authorizes a covert mission to bring Juana to the capital for safety and their marriage.

He relays mission details to Juana via military telegraphs. Amatsukami intelligence intercepts and decrypts these transmissions, compromising both the primary escort and the backup plan involving pilot Charles Karino. This breach inflicts significant losses on Levamme forces, including decoy units. Carlo's actions directly enable the story's central conflict, yet he faces no depicted consequences for the intelligence failure.

After Karino successfully completes his mission, Juana arrives safely. She marries Carlo, becoming Empress of the Holy Levamme Empire. Carlo's subsequent role, including any involvement in Juana's peace efforts, remains undocumented. He appears in no other confirmed media within the narrative universe. Carlo Levamme's physical appearance, personality beyond his political role, direct character interactions outside operational decisions, background prior to the marriage, and activities following Juana's ascension are not elaborated in available sources.