Hae-sung (by Yeo Jin-goo) disappears after a mysterious accident. 12 years later, he wakes up on the roof of his school building. He is now 31 years old, but he still has the appearance and personality of himself at age 19 when he disappeared. He reunites with Jung-won (by Lee Yeon-hee), his childhood friend and first love. The two of them end up being 12 years apart because Hae-sung was gone to another world. Hae-sung’s siblings were all separated after his death, so he brings them together. He later finds out that he was unjustly accused of killing someone after he died. To solve the mystery of his death and clear himself of a false charge, he begins his own investigation. Accompany him on this fantasy romance journey to find out where he will be at the end of the road.

原本青梅竹馬的成海誠（呂珍九 飾）和鄭靜媛（李允熹 飾），在高中的時候因為特殊原因而分開，鄭靜媛一直以為成海誠已經去世。但是，12年之後鄭靜媛又再次遇到了成海誠。成海誠仍然是18歲的模樣，而此時的鄭靜媛已經31歲了。但是，兩人心中依然有著彼此，於是一段特殊的愛情就這樣開始了。