Princess Britania ~Muse no Houken~

The protagonist Chloe is the heir of the great house of Sheffield whose warriors have long served the queen of Britania. Britania has been at war with the neighboring Hilbenia Republic for many years. At long last, the two nation's leaders have met to create a peace treaty. But the newly created peace is quickly threatened when the Hilbenian prince and his royal party are attacked on their way back home. It falls to Chloe to root out the truth of the attack and prevent their countries from falling back into war.