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..