Aeris de Crosse is the brash and tomboyish commander of the Reginia Imperial Army who wields the coveted crimson sword, Camellia. A revered warrior and prestigious leader, Aeris has no plans of leaving her position even if she does happen to be the crown princess. Tsubaki Koizawa is the arrogant and bratty emperor of Yamato and unbeknownst to him, he has been a long-time, arch nemesis to Aeris.
In the height of a fierce war between Reginia and Yamato, the king of Reginia reaches a deal with the emperor of Yamato, which ends the war and restores peace between both countries. Aeris returns home victoriously from the battle to find that someone forgot to mention that she was a part of the deal. Now, she’s being forced to marry her arch enemy, and Tsubaki ends up getting more than what he bargained for. Will the two learn to come together for the greater good or will they be the cause of the next world war?