"사도" (Sado) refers to a historical figure in Korean history, specifically the son of King Yeongjo of the Joseon Dynasty. He is known for his tragic life and untimely death, which was largely influenced by his mental health struggles and the rigid expectations of royal life. Sado was famously confined to a rice chest by his father, leading to his death by starvation. His story has been depicted in various forms of media, highlighting themes of tragedy, familial conflict, and the pressures of royal duty in Korean history.