At a difficult place in his marriage and career, a middle-aged man gets a shot at a do-over when he's transformed back into his 18-year-old body.

Ace NIS agent Jung Hae-seong is demoted after a mission failure. He goes undercover at a high school to locate King Gojong's missing gold, meeting his teacher Oh Soo-ah, who sees him as her lost first love, stirring old heartbreak.

A K-pop star, Sa-gye, reluctantly enters college, forms a 4-member mixed band, and navigates love and growth through music amid the chaos of campus life.

Jin Nam-joo gets dumped by her boyfriend, whom she believed was fate, on the first day of the new year. Her fortune-telling dad predicts that three men of destiny will appear before his daughter.

Kang Hye-in secretly marries Choi Hyun, Korea's biggest star, and endures contempt and betrayal alone in their hidden marriage. After the tragedy of losing her child, she decides to divorce him. With the separation, the life Hye-in kept from Hyun quietly begins to unfold, and the moment she lets everything go, her life takes an unexpected turn.