Does this have incest?

Nope

Aight thanks bruv

Lmfao bro got played

There is literally no incest tho

well if the op considers step siblings as incest then there is
otherwise there isn't

They are not step siblings. Mc himself says that they are not blood related. To be step siblings you need to have a blood relation from at least one side

then what do you call kids adopted in the same family?

I call it “not incest”

I wasn't asking what you call their sexual relationship. I am asking what do you call them in normal relationship?

Um I believe what u are referring to is a half sibling . A half sibling is where u need at least blood relation from one parent in both kids. A step sibling is different that is when u have no blood relation and are from two different families. So there is no blood relation between the two characters in this manwha I still consider it weird but it’s not incest that’s for sure.

I have no problem with this but I said it's incest (if you consider it) because maybe the op is uncomfortable with it. Me personally I like the story. You don't but maybe the op sees it as incest that's why. It's not incest for you and me but maybe for some.