Born to Lady Yuhwa, a concubine of King Geumwa of Dongbuyeo, and Hae Mosu, Jumong excels in martial arts and possesses a lively spirit, leading to severe abuse and conspiracies from the East Palace due to jealousy. Unable to bear it, Jumong one day leaves his mother and his beloved Yerrang to search for his biological father, King Hae Mosu. However, the king has already passed away, and the country has fallen into chaos due to the disturbances of ignorant bandits. Faced with this situation, Jumong defeats the bandits and Princess Nakrang, and then founds Goguryeo. Jumong becomes king and enjoys all sorts of glory and wealth, but he cannot forget Yerrang, whom he parted with when leaving Dongbuyeo. He falls into despair upon hearing the news of Yerrang's death. Yerrang, whom he believed to be dead, gives birth to his son and becomes a beggar, wandering in search of Jumong.