It's a drama that probably appeared between 2010 - 2016.
Multiple generations live in the same house (grandparents, their son and his son's family, aka wife and children, not sure if there were others), the grandfather is a strict man that is never satisfied with his son's work/behavior.
One day, outside, he meets a young man that helps him out. They bond a lot and become friends (bromance). They have a lot of sweet moments together, in one scene the younger guy gives the older one a piggyback ride, or they share an umbrella (if I am not mistaken).
The grandfather actor looked like (maybe even was) Lee Deok-hwa or Woo Hyun.
Anyone knows this drama?