For five centuries, the Taboo Emperor Arthur Gaz governed the Gaz Empire with an iron grip and carried out cruel experiments on his own subjects. His rule ended only five years ago, when the legendary Eight Heroes conquered the capital and toppled him. His fall brought an end to the three‑hundred‑year conflict between the Gaz Empire and the coalition of six states.
Today, Tooru Acura—once a saboteur in that war—struggles to adapt to the calm of peacetime, unable to find work that lets him use his combat prowess. Fate intervenes when he encounters the white‑haired sorceress Chaika Trabant, who carries a coffin and seeks to recover her father's scattered relics for a proper burial. She enlists Tooru and his adopted sister Akari to aid her quest. Yet the former alliance, now called the Council of Six Nations, sends Albéric Gillette and agents from the Kleeman Agency to track down Chaika, the daughter of the fallen Emperor Gaz.
When Chaika"s true lineage is uncovered, the Acura siblings face a dilemma: assist her in collecting the emperor"s remains or preserve the fragile peace that the continent now hopes to hold.