River Where the Moon Rises

Jinheung of Silla

Queen Yeon, the former Queen of Goguryeo. A brave and intelligent woman, she works to protect Goguryeo from evil tribe leaders but is killed by Go Won-pyo at Sunnobo. She is the mother of Princess Pyeonggang and Prince Go-won.

Young Princess Pyeonggang

On Dal Seo Dong-hyun as young On Dal

General Go Geon Park Min-sang as young Go Geon

Hae Mo-yong Moon So-hee as young Hae Mo-yong

Lady Gongson, nanny of Princess Pyeonggang. She is a loyal person who is guarding the empty Gongju Palace (Magnolia Palace) alone, hoping that Princess Pyeonggang, who disappeared 10 years ago will return alive, and then becomes a shadow of Pyeonggang after Pyeonggang comes back alive.

Queen Jin, a figure who won the king's heart with her outstanding beauty and manner. She is the mother of Prince Geon-mu, she seeks the chance to drive out Prince Go-won and make Prince Geon-Mu the king.

Prince Go-won, Princess Pyeonggang's younger brother and the person who encourages On Dal to participate in the war. Park Sang-hoon as young Prince Go-won.

General On Hyeop, the father of On Dal and the head of the Sunno region in Goguryeo. His is a dutiful leader who fulfills his responsibilities for his country and his people. Embodying a sense of charisma and righteousness, he is a revered general of the people who receives support and loyalty from the masses.

Lady Sa, the nanny of On Dal. She took care of On Dal after his father's wrongful death and the only remaining family of On Dal.

Sa Pung-gae, the son of commander Sa Woon-am and On Dal's childhood friend. Kim Hyun-bin as young Sa Pung-gae

Wol-yi, a Baekje refugee and playful child who uplifts everyone in the Ghost village.

Tarajin, a killer who lives with her twin brother Tarasan, in Dorim-hyang, where people abandoned in Goguryeo gather.