Actor Kim Ha Neul, YunSang-hyun, Lee Do hyun

Introduction: Hong Dae-yeong, an average 35-year-old man, was a hot teenager in high school. Everyone would scream his name and think of him as their first love. However, he destroyed himself by drinking and smoking, ending up as the icon of drastic change. Nevertheless, he thought he was an average middle-aged man – until he got divorced, got fired, and was left with nowhere to go. He did his best for his family, but they treated him like an old shoe. What was he to them? Feeling pathetic and hopeless, he goes to his high school and makes a wish by throwing a basketball. “Let me go back!”As if the heavens listen to his words literally, Dae-yeong sees that he's 18 again! Given a second chance, Dae-yeong changes his name to Go Wu-yeong and starts his new life. But when he finds out that his ex-wife is seeing another man, he must fix his relationship with ex-wife -as a high school student!