
I’ve read the novels & my understanding is that the brother &sister are not blood related, but because she’s older she didn’t think he knew. It’s explained in the novel that she was from a previous marriage of the 1st wife of the ML’s dad(her stepdad).That is also the reason why she’s obsessed with being accepted by the father & inheriting the company. also why she is beta when everyone else in family are alphas.

i've read the novel too. But used google translate when reading that time and here i thought they are of same dad. Thanks for clarifying this part.
I wonder though that if they aren't related by blood, why is the father too had to set him up to marry someone else knowing ML's in a relationship w/ Sooha. ML has his own life already but his dad had to get involve. Or did I miss something..

The father is just a disgusting piece of shit. Remember the contract or he'll be stuck there forever? Isn't he already stuck there forever? He's already been there at least 15 years and he said before he has another 10 years to go to pay it off, only if he keeps being r*ped on the father's whims. He can't leave the house or have any type of life and that's on top of 24/7 slave labor.
Ok. This is starting to get kinda cute.