Gye Baek was born as the son of Mu Jin, a student and guard of Baekje's King Mu, but because of his father being falsely accused, he grew up as a commoner in the market streets.There, he meets a merchant named Eun Go and he falls in love with her. One day, after getting caught up fighting in the mountains, Gye Baek is lowered to become a war slave and becomes a prisoner of war for Silla. At Silla, he reunites with Uija who came as an envoy and learns there is a great secret about his father's death. Though King Uija and Gye Baek have a strong friendship, they both have feelings for Eun Go at the same time. Gye Baek's loyalty to Baekje and King Uija completes a history page. What will the situation be in the relationship of Uija and Gye Baek with Eun Go in between?