16 year old boy, A-Reum has Progeria Syndrome, a rare genetic defect that will cause the baby to show rapid aging from an early age. Although A-Reum has struggled again the disease, he was raised as a brilliant young child than anyone else. Young parents, Mira (SONG Hye-kyo) and Dae-su (KANG Dong-won) are still in their early 30s who had A-Ruem when they both were 17 year old, sometimes act immature but they never expressed their sorrow. A-Ruem only has few month to live, and Mira and Dae-su want to denied the reality. Although knowing that he does not have much time left, they appear on a fundraising TV show in hopes of raising enough money for his medical care. A-Ruem's appearance on a TV brings everyone's attention, and he becomes pen pal with a teenager girl who's also suffering from a disease watching the show. Exchanging letters with her becomes the joy of his days. But his body becomes more weary from aging, and he even loses his vision. Written by KOFIC