Reunited Worlds

Sung Hae-sung (Yeo Jin-goo) is a senior high school student. On his birthday, his girlfriend Jung Jung-won (Jung Chae-yeon) prepares a surprise party for him at his house. To keep Hae-sung away while they set up, Jung-won asks him to go to their school and retrieve her wallet. There, he stumbles upon a shocking scene where a bully was found dead. While trying to get help, he is hit by a car and dies. Twelve years later, Hae-sung mysteriously wakes up on the roof of his school building, unchanged as a 19-year-old, while everyone he knew has aged. He reunites with Jung-won (Lee Yeon-hee), who is now a 31-year-old woman, and with the help of his friends, he sets out to uncover the truth behind his death and his sudden resurrection. As Hae-sung investigates, he discovers that after his death, he was accused of killing the bully. The real culprit was someone else, but Hae-sung was blamed, leaving his family and friends to suffer in the aftermath. Realizing that his resurrection has a purpose, Hae-sung dedicates his time to making things right. He helps his siblings, who struggled after his death, and supports his best friend, who was deeply affected by the false accusations against him. However, he soon learns that his return to the world is only temporary. He was given this second chance not to live again, but to resolve the past. As he brings the truth to light and ensures justice is served, his presence begins to fade. In a heartbreaking farewell, Hae-sung shares final moments with his loved ones, including Jung-won, with whom he shares a deep, unbreakable bond. Though they love each other, they must accept that they now belong in different worlds. With a peaceful heart, Hae-sung disappears, leaving behind a legacy of love, healing, and closure for those he cherished.