Hoseok is a 22 years old penniless money, but what happen if an old man suddenly approches him and offer a nanny job?  "Why me?"  "Don't worry, the one that you will take care is not a 5 years old boy" "But-" "So, would you like to take this offer or not?" "I...Will take it" And that's where his new life begin, along with his love story with a sick 21 years boy..