Although originally born in the same year, two childhood friends end up being 12 years apart because they have aged at different places (worlds) for some strange reason. Sung Hae Sung disappears after a mysterious accident. 12 years later, he suddenly appears again. He is now 31-years-old, but he still has the appearance and personality of when he was 19. Sung Hae Sung gets involved in a romantic relationship with his childhood friend Jung Jung Won who is now 31-years-old. Jung Jung Won's boss, restaurant owner, and main chef Cha Min Joon is also in love with her.