
There won't be any romance with those girls, right? I mean..I think they're all basically cousins...

Idk if it's the same setting in this story, but if the girl's are from 'indirect family' it doesn't automatically means they are cousins. Some of them are a separate family, w/o any blood relation, accepted by the main family.
There are also those from the main family but are originally orphans just talented, hence they were adopted.
I actually kinda likes this kinda trope, very refreshing except the ml's eyes looks kinda weird