A couple of teenagers have a son who suffers from progeria, a rare genetic disorder which makes one age exponentially faster than normal. 16 years later, the child has the body of an 80 year old in the final days of his life writing a book about his parents' love story.

A love story between Jae-hoon, who couldn't let go of his ex-girlfriend, and Seon-young, who is splitting up with her boyfriend. The couple got trouble and were hurt by love.