The reason the wall paper is the same is because the set designer used his 20% coupon at Home Depot !!! And while we're on the subject of everything being the same on different dramas....The living room always has the "Head Armchair" where the head of the house sits, and then a sofa with a back on one side, and a sofa without a back on the other side of the armchair. And everyone eats fruit all cut up with a fork! The house on Likeable or Not is very similar to the style of house in High As the Sky.
My grandmother had those little forks and they look exactly the same but I never knew what they were for. I was watching my first drama a little bit ago and I thought"Ohhh, so that's what those are for". She never used them around me but for some reason I wish she did About those wallpapers, I have seen those a few times as well but, the only drama I've seen that was way different from the style and culture you see in most k dramas was coffee prince. The set looked like american apartments and none of them lived with their parents
My husband's family does a lot of things I thought weird. (salt on fruit; brushing the teeth with anise sticks (toothpaste, too); peeling an orange or grapefruit in a spiral and hanging up the peel in the house.) Now, forty plus years later, I'm doing them too.