The Great Show (2019)

in the part of not knowing about the existence of leaving a woman with children and that after a while it is revealed that the father is her children.

similarities-
father based
take in a kid that's not theirs
snip it's of the kids life
make you smile and cry
*the show is 52 episodes but its a worthwhile watch*

I am surprised nobody recommend this
it gave similar feels since ep 1
both family series and children make it cute
while there is still some seriousness with the main couple and some romance

Both revolve around adults who attempt to use kids for their own interests and then end up growing attached to them.

on the first side both has tried to hide the kids .
but they grow on their tasks and overcome the fear of society.

Also both are not the parents related to blood but they do everything for raising them in a good way.

Both dramas are political comedy romances about assemblymen/women; they both have a strong family element with the opposition trying to use their family situations against them; they both have conservative verses progressive issues and relationships they want to keep private.

the main element for both dramas is the ml running for national assembly and in some ways both are about "faking a great show" to appeal to the public.

both male characters discover a child they didn't know about, though in Oh! My Lady the ml tries to hide that fact while The Great Show ml uses it for his advantage. also both female leads help the male lead take care of the kids.