Maybe he owns the whole floor? And maybe they are across from each other? Maybe he came after dad left or it could be different buildings just in case something like this happens? Maybe A is in Sejun’s or a false name and B is in his? People with Money and who have enemies do that kinda stuff for those they love and want to protect.
I think A is one floor and B is a different one
The room is probably on the other side of the floor considering how big the apartment is maybe thats why they didnt cross path
I think they just arrived at different times but we’ll see
:O