Gunshin no Hanayome

Sakura, caught between a successful older sister and an attractive younger one, has led an ordinary existence. She is abruptly taken away to become the bride of Kai, a prince nicknamed the "God of War." The marriage is not based on affection but due to her ability to wield the "Sword of Demon-Slaying." Held in confinement, Sakura's potential to influence Kai, a man devoid of warmth, remains uncertain.