lol. I remember when I watched a few J-dramas and many of them had some of the same actors or actresses. I just think a person who is liked a lot gets hired a lot. Kinda like at some points you can see certain Korean actresses or actors everywhere
I swear they cast the same group of people for the moms, grandmas, and chaebol father/grandfathers because I see them in every drama. And there's this one actor whose face I keep seeing in nearly every drama I've seen: Orange Marmalade, Cheese in the Trap, Mirror of the Witch (appeared in the 2nd to last episode), Surplus Princess, etc. He usually plays the side characters, usually the dad, but his face is everywhere lol.