There was a female knight who was said to be the strongest in the kingdom. Yuri Lambert was the commander of the first division of the kingdom's knights. However, the knights were a male-dominated society, and as a female commander, Yuri was not loved by her subordinates . But Yuri didn't mind. In order to protect her knight family, which was on the verge of decline due to the lack of males, she abandoned her womanhood and became a knight, and since she was able to protect her family, she had no regrets. The empire then invaded the kingdom where Yuri lived. The kingdom's soldiers were outnumbered and outpowered by the emperor's soldiers, and Yuri was the only one who was fighting well. Then the enemy emperor appeared on the front line and challenged Yuri to a duel. "If you win, I will stop the invasion of the kingdom." Yuri had no way of refusing the enemy emperor's offer, so she accepted the duel. However, the emperor's power was overwhelming, and she was defeated without being able to do anything. However, for some reason, Yuri was spared and imprisoned. What could the emperor's intentions be...?