Rakuin no Monshou

Two nations, Mephius and Garbera, have been at war for a decade and seek to end hostilities through a marriage between their royal families. Orba, a man displaced by the conflict and now a gladiator, bears a striking resemblance to Mephius's crown prince and is chosen to impersonate him during the wedding. Meanwhile, Garbera's princess, Vileena, has made a secret decision to manipulate the crown prince for the benefit of her own country.