In the midst of the 4th year of King Sejong's reign,
Crown Prince Lee Yool is on his way to meet the King when he gets into an accident that leaves him with amnesia. When he awakens, he finds himself in the body of a commoner named Park Hae-young, but retains the memories of being the Crown Prince. Park Hae-young, a poor but kind-hearted man, tries to navigate his new life while holding onto his royal past. He meets a woman named Shin Chae-kyung, who is a noble and the daughter of a high-ranking official, and becomes embroiled in her family's complexities.As Lee Yool navigates his new life, he discovers that his memories of being the Crown Prince are starting to fade. Desperate to hold onto his true identity, he tries to find a way to return to the palace, but his attempts are constantly thwarted by the strict rules of the royal court and the suspicion of those around him. Meanwhile, Shin Chae-kyung finds herself falling for Park Hae-young, unaware of his true identity as the Crown Prince.As Lee Yool's memories continue to fade, he becomes increasingly desperate to reclaim his rightful place on the throne. He forms a plan with Shin Chae-kyung to infiltrate the palace, but their efforts are met with resistance from the opposing forces of the royal court. With the help of a group of loyal servants, Lee Yool manages to gain access to the palace, but his true identity is eventually discovered, leading to a dramatic
confrontation with the King and the royal officials.Throughout the series, the characters face numerous challenges and obstacles as they navigate the complexities of the royal court. Lee Yool's struggle to reclaim his rightful place on the throne is a central theme, as is the romance between Lee Yool and Shin Chae-kyung, who find themselves caught in a web of deceit and duty. As the series unfolds, the characters are forced to confront their own motivations and desires, leading to a dramatic and emotional conclusion.