Lee In is a prince. His older brother is King Lee Sung and he cares very much for him. Li Ren pledges loyalty to his brother and is taken hostage by the Qing Dynasty. King Yi Sung soon sees his brother’s loyalty as a betrayal and begins to hate him. As a result, Lee In suffers deep mental pain.
Later, Li Ying meets an unknown shogi player who bets on her game. He is completely fascinated by Baduk players. Due to circumstances, Lee In becomes the king. He has the highest position and is a strong person, but inside he is sad and weak.
When Kang Hee Soo became famous as an unknown chess player, she met and fell in love with Prince Lee In. By a twist of fate, she becomes a spy. She approaches King Lee In for revenge.