Responses
SPOILER
it was confusing to me too but they're not related. eron/rowoon's dad was chairman shin's business partner. sera's dad is different, i think her biological dad was chairman shin's...secretary? so different dads but confusing because they looked similar and died around the same time
even then they were raised as siblings
Jia han ended up with ro-un lee not sera shin aka his step sister he grew up with
whyd she end up w her brother yuck