Juyeong is in a juvenile jail center for attempting to murder his father, Gang-ryong. He clings to hope, seeing a future in Seoul with his boyhood friend Dayeon. But everything is shattered when Dayeon is cruelly murdered by a rogue truck, and Juyeong’s grief grows when he discovers that his father was driving. In a tragic twist, Gang-ryong regains consciousness and issues an ultimatum to Juyeong: “If you want revenge, become the king of this detention center!” Now, Juyeong must traverse the perilous world of prison politics, aiming to ascend to power and avenge his comrade.