Shin Yool is the princess of Later Balhae, and she narrowly escaped death as a child at the hands of her own people because of a prophecy that she is fated to become "the light of another nation".
Shin Yool adalah putri terakhir Balhae, dan dia lolos dari kematian sebagai anak di tangan orang-orang sendiri karena ramalan bahwa dia ditakdirkan untuk menjadi "terang bangsa lain".