Title: 다시 만난 세계 / Reunited Worlds
Also known as: Into the New World
Genre: Fantasy, Romance, Comedy
Episodes: 40
Broadcast network: SBS
Broadcast period: 2017-July-19 to 2017-Sep-21
Air time: Wednesday & Thursday 22:00 KST (2 episodes back-to-back)

Two childhood friends born in the same year, Sung Hae-sung (Yeo Jin Goo) and Jung Jung-won (Lee Yun Hee), who get separated during their high school years due to an incident that causes the disappearance of Sung Hae-sung. They meet again 12 years later when the woman is already 31 years old but the guy is still young at 19. His physical appearance is the same as when he disappeared 12 years ago.